The Correction of Presbyopia with Contact Lenses - Optometry in ...

Optometry in Practice Vol 8 (2007) 19–30
The Correction of Presbyopia with Contact
Lenses
Caroline Christie 1 BSc(Hons) FCOptom DipCLP and Ron Beerten 2 FAAO BCLA
1 2 NF Burnett Hodd Practice, London. Procornea, Eerbeek, The Netherlands.
Date of acceptance 19 October 2006
Introduction
The onset of presbyopia creates a wealth of patients
looking for alternatives to spectacles. Reading glasses are
seen as an admission of ageing and a step back from what
and where patients used to be. It is a misconception that
bifocal/multifocal contact lenses do not work and are
difficult to fit. However, it is challenging and sometimes
confusing to manage all the options for the correction of
presbyopia with the seemingly vast range of contact lenses
available today. The secret of success is to find the right
design for the right patient.
The choices available to correct the presbyopic contact
lens wearer include:
• Modified distance vision
• Use of reading spectacles in conjunction with contact
lenses
• Monovision
• Alternating (translating) bifocals
• Simultaneous multifocals
o Spherical
o Aspheric
Modified Distance Vision
By undercorrecting the myope or overcorrecting the
hypermetrope for distance, a marginal improvement in
near vision may be obtained. This clearly will only be
helpful for the very early presbyope and will prove of
limited value for the newly fitted myope who will already
be exerting more accommodation and convergence with
contact lenses for near vision than with spectacles. In any
event, the option is only a short-term solution and at best
may serve as an interim measure until a more permanent
alternative can be produced.
© 2007 The College of Optometrists
19
Use of Reading Spectacles in Conjunction
with Contact Lenses
Whilst this is the simplest option for the correction of the
presbyopic contact lens wearer, it does not address the
problem for the patient who does not wish to wear
spectacles. Nevertheless, the quality and stability of vision
in this mode of correction are such that it may prove to be
a necessary additional method of correction for those who
need a more stable and better quality of near vision than
can be provided with bifocal contact lenses.
Monovision
This is the least complicated method by which to provide
presbyopic correction using contact lenses. Since lenses
employed are of the single vision type, fitting is by
conventional means and the addition for near is provided
in the non-dominant eye, using the minimum plus that
affords adequate near correction.
Many practitioners still use sighting dominance tests
(such as hole in the card, pointing finger) to confirm the
dominant eye. However there is no scientific literature
relating sighting dominance to blur suppression. Sensory
dominance tests (fogging techniques) are far more likely
to be predictive because they are a direct measure of the
patient’s ability to suppress an out-of-focus image.
The +2.00 blur test is acknowledged as being one of the
best and simplest clinical methods of identifying the
dominant eye. The test is carried out with the patient fully
corrected for distance vision. The patient is asked to
observe binocularly a distance target and a +2.00 DS trial
lens is held in front of each eye in turn. The patient is
asked to decide under which distance viewing option the
vision is least disturbed and the eyes feel most
comfortable. Once the preference is decided the
practitioner should record which eye the +2.00DS lens is
currently in front of, and this is defined as the nondominant
eye to be corrected for near vision.
Address for correspondence: Caroline Christie, NF Burnett Hodd Practice, 7 Devonshire Street, London W1M 5DY, UK.

C Christie & R Beerton
Where there is no particular preference the decision as to
what eye is to be selected is made bearing in mind other
factors such as residual astigmatism and corrected acuity.
It is totally unsuitable for amblyopic patients.
Monovision is an extremely successful option for early
presbyopia (Davis 2003, Efron & Morgan 2006) and
quoted success rates vary from 67% to 86%. However,
there is usually a decreased level of stereo acuity at near
and slightly decreased contrast sensitivity. The degree of
interocular blur suppression (which varies between
individuals) may be linked to the final success of
monovision. The most commonly reported problem with
monovision is glare when driving at night.
For most patients, once the addition reaches +2.50D, the
disparity between the two eyes may be difficult to accept.
The lowest near add possible allows quicker adaptation to
the concept and better intermediate vision.
Partial monovision, where a low add of +0.50 or +0.75
gives sufficient convenience for intermittent near vision
(to read price tags, menus, headlines) and patients are
then happy to use additional reading spectacles for
prolonged close work, can often prove successful where
full monovision has failed. The over-reading spectacles in
this instance however require to be properly balanced and
not off-the-peg ready reading glasses, with the same
prescription for right and left.
The authors feel the most important indicator of success
is the patient’s initial impression: if the patient does not
feel disoriented in the consulting-room environment, then
it is worth proceeding with a monovision trial (Morris
2003, Norman 2006b, Stiegemeier 2006).
Alternating (Translating) Bifocals
The basic principle underlying the alternating design is
that, as the patient looks down, the lens rides up and the
near segment covers part of the pupil, allowing the patient
to read. When the patient looks straight ahead, the lens
recentres and the visual axis passes through the distance
portion. Alternating designs have the best potential for
crisp vision at distance and near, but they are gazedependent
and may be unsuitable for prolonged computer
use. In cross-over trials they have been shown to be as
successful as monovision, but the fitting of an alternating
design requires skill, time and experience. There is
minimal contrast loss but some flare with larger pupils and
it can be difficult to achieve inferior lens positioning,
particularly in myopes. Alternating designs have ‘jumpfree’
or monocentric optics.
20
Until recently, alternating designs have almost exclusively
been available as rigid gas-permeable (RGP) lenses since
no soft alternating lens had been found to work reliably, be
comfortable and physiologically acceptable for long
periods of wear.
Alternating designs are similar in construction to a bifocal
spectacle lens and both solid and fused constructions have
been available. Solid alternating lenses have a lower
segment and perform in a similar fashion to a spectacle
bifocal lens. Prism ballast is used to orient the segment in
the correct position and may be further stabilised with
truncation inferiorly (Benoit 2005, Davis 2003, De Carle
1997, Morris 2003).
RGP translating designs
The Fluoroperm ST bifocal has a straight-top, highrefractive-index
segment encapsulated within the lens
(Figure 1). The anterior and posterior surfaces are smooth
and the segment is monocentric, ie the optical centre of
the segment is located at the segment top to give ‘step-free’
vision. Despite the use of prism for stabilisation, the lenses
are thinner and lighter than the solid segment Tangent
Streak design (Davis 2003, Morris 2003). Fluoroperm ST
bifocal is now discontinued because of difficulties in
manufacturing stable, predictable and reproducible
parameters.
The Tangent Streak bifocal (also available as a trifocal)
consists of two wide segments meeting at a straight
horizontal junction, similar to an executive-type spectacle
bifocal (Figure 2).
The segment of the PresbyLite bifocal is triangular in
shape (Figures 3–5). This makes the design more
independent of pupil diameter, compared to straight-top
bifocals. This means the same distance and reading
performance is provided, even in different light
conditions. Another advantage of the triangular segment is
that less translation is necessary for optimal visual
performance. The segment, which is only a few microns in
depth, is cut from the front surface with no noticeable
transitions. This aids in wearing comfort, reduces
reflections and shortens adaptation time. The triangular
sectored near area allows up to 30° rotation without visual
disturbance. The initial designs (first-generation) had a
spherical back surface, included the use of prism ballast
and truncation and offered two segment variants. This
made fitting the lens complex and large amounts of prism
were often required to prevent high-riding fits.

PresbyLite 2 (second-generation) has a new aspheric
back-surface design. This provides easier translation,
needs only a minimal (standard) prism for stabilisation
and rarely requires truncation. Combined with the use of
larger diameters, this is a benefit for this type of
alternating design (Davis 2003, Van der Worp 2006).
As the name suggests, concentric lenses have concentric
rings of power that may involve a centre distance (CD) or
centre near (CN) configuration (Benoit 2005, De Carle
1997). The Menifocal Z is a concentric design bifocal with
21
The Correction of Presbyopia with Contact Lenses
a distance optical zone, a unique transition zone which
helps to reduce the degree of blur and doubling, plus a
peripheral optic zone for near (Figure 6). As the add
increases, both distance and transition zones reduce,
allowing the reading area to become larger. The front
surface is aspheric, which contributes to the effective add
power, and there is a spherical back surface to simplify
fitting. This bifocal requires translation of the lens on
downward gaze. The fit requires the lens to position
centrally with free and rapid movement (Ghormley 2003,
Lakkis et al. 2005).
Figure 1. Straight-top bifocal. Figure 2. Tangent Streak bifocal in situ.
Figure 3. Triangular shape segment. Figure 4. PresbyLite.
Figure 5. PresbyLite in situ.
Figure 6. Concentric translating bifocal, centre distance.

C Christie & R Beerton
Figure 7. Triton soft bifocal (straight top). Figure 8. Royal soft bifocal (triangular segment).
Figure 9. Aspheric multifocals: gradually changing power curve
centre near or centre distance.
Figure 11. Topography demonstrating corneal moulding.
Figure 13. A CD D lens is used for the dominant eye and a CN N
lens for the non-dominant eye.
22
Figure 10. Back-surface aspheric design in situ.
Figure 12. AcuVue bifocal.

Soft translating designs
This was a very short story for years, the reason being that
soft translating designs simply weren’t available! Due to
the relatively low success rate, especially in higher adds of
soft simultaneous designs, in terms of visual acuity for
both distance and near, much research has focused on
developing translating soft multifocal lenses (Ghormley
2003, Norman 2006b). The most difficult problem to solve
is how to get a soft lens translating, without losing
comfort.
One example of such a lens is the Triton bifocal contact
lens, developed and designed by Gelflex Australia and
launched in 2000. The lens features a straight-top near
segment in the inferior part of the lens, quite similar to the
basic design of many RGP translating bifocals (Figure 7).
To provide translation, this lens has a truncation resting
on the lower eyelid, pushing the reading segment in front
of the pupil while gazing down. The back-surface design
allows the lens to translate easily. Stabilisation is achieved
by truncation and prism ballast. Toric versions are
available (Morris 2003).
Although the principle does work and offers excellent
visual acuity for both distance and near, it is not always
ideal for patients. Failures generally occur due to
discomfort and long-term physiological problems due to
the low Dk/L (thick design) in conventional materials and
the truncation.
A new approach is the Royal bifocal contact lens,
introduced in the UK in 2006. A triangle-shaped reading
segment (based on the same principle as the PresbyLite
RGP bifocal lens) is located on the front surface in the
inferior part of the lens (Figure 8). Two segment types are
available: the full triangle (Distance Zone 0) and a ‘topless’
variant (Distance Zone 2), which is the standard version.
Situated just below the reading segment on the front
surface is an arched zone: when aligned with the lower
eyelid, this zone enables the lens to be pushed upward
when the gaze is directed downwards to make reading
possible. The specially designed back-surface geometry
aids in easy translation. Stabilisation is achieved by a
combination of prism and dynamic stabilisation. This
results in a relatively thin design, which is a benefit in
terms of wearing comfort and corneal physiology. The lens
is available in a toric option from 0.75 to 3.00DC.
Tips
• All translating lenses must move freely upwards on
downward gaze to bring the near portion in front of the
pupil.
• The lens (segment) needs to sit slightly low in the
23
The Correction of Presbyopia with Contact Lenses
primary position and, although good translation
(movement) on downgaze is required, the lens must
recover quickly after each blink so as not to disturb
distance vision (particularly during driving).
• The patient’s lower lid must have sufficient tone to hold
the lens stationary when the eye rotates downwards.
• Ideally the lower lid needs to be positioned at a point
that is no lower than the lower edge of the visible iris.
To assist the lid in locating against the lower edge of the
contact lens, the edge profile of the contact lens may
need to be relatively square in cross-section rather than
the normal tapered and rounded edge.
Translating bifocals in summary
Advantages
• Excellent visual acuity for distance and near
• Good contrast
• High near adds available
• Wide range of parameters
• Toric options available
• Normal stereopsis
Disadvantages
• Stabilisation necessary (prism ballast)
• Gaze-dependent
• Intermediate distance?
• Lens required to be very mobile on eye
• May require to be truncated
• Comfort?
Simultaneous Multifocals
There is potential for some confusion in using the term
‘multifocal’ as this implies a similar mechanism to a
multifocal spectacle lens. However the basic principle of a
simultaneous design remains the same irrespective of
whether the power of the lens varies in a discrete or
progressive manner across the surface. Simultaneous
vision bifocals produce an optical system that places two
images on the retina at the same time and then relies on
the visual system to select the clearer picture.
Good centration and stability of fit are required for
optimal performance (Morris 2003). One of the main
problems with these lenses is a loss of contrast sensitivity
within the superimposed retinal images. The problem is
worse in low illumination and can give particular
difficulties with near vision.
Despite many attempts to improve the visual
performance, some loss of contrast always occurs with

C Christie & R Beerton
simultaneous designs (Hough 2002). Although they are
gaze-independent, the balance between distance and near
is almost always influenced by the level of ambient light
(pupil diameter). Some designs on the market exploit or
control spherical aberration in an attempt to enhance the
refractive effect, since there is no need to depress the gaze
in order to read. This has an obvious benefit for certain
occupations (prolonged computer use). For advanced
presbyopes ‘top-up’ spectacles will often be required,
although only for certain specific tasks.
With aspheric simultaneous designs a gradual change in
curvature on either front or back surface provides the
required reading addition (Fischer 1999).
These designs may be of the CN type (maximum plus at
the centre of the lens, decreasing peripherally and
employing front- or back-surface asphericity) or of the CD
type (minimum plus at the centre of the lens, increasing
peripherally and employing front- or back-surface
asphericity: Figure 9).
Although available in RGP, soft and, more recently,
silicone hydrogel material, these lenses all share one
essential drawback. Since the asphericity is the only
means of providing the addition, there are implications
for the range and quality of vision. The greater the
eccentricity (or rate of flattening), the higher the reading
power in relation to distance power. However, the higher
the reading addition, the more likely it is that distance
vision will be adversely affected, especially in low-contrast
and/or low-light conditions. For this reason, aspheric
lenses often work well in early presbyopes where the
required add is low and the compromises on distance
vision are minimised. It is essential that any aspheric lens
centres well on the eye. If it does not then the visual
performance will automatically be substandard.
Front-surface RGP aspheric simultaneous designs
produce a power curve which increases from the centre
out to the periphery. This means that the majority of
lenses are CD. By controlling the spherical aberration
within the power gradient there is a smooth transition for
distance to near, which is why they are often referred to
as having a true ‘multifocal’ effect.
Concentric simultaneous designs employ two distinct
zones, with either the central zone being used for reading
(CN) or for distance (CD). With some of these designs
practitioners can select the size of the central zone
according to specific requirements, whereas others have
fixed zone diameters related to the amount of add power
required.
24
RGP aspheric multifocals are available with high and low
eccentricities.
High-eccentricity designs
• High-eccentricity designs are typically fitted very
steep, as much as 0.60mm steeper than flattest K
• Good centration is essential
• A central fluorescein pool will be seen
• Posterior aspheric designs can provide an effective
near addition up to +2.50DS
• The greater the near add, the smaller the distance zone
The No7 Quasar Plus lens is a CD bifocal created via a
back-surface RGP aspheric design. The back surface of
the lens is made significantly steeper than the cornea and
the add power increases with eccentricity (Figure 10). It
is generally fitted 0.4mm steeper than flattest K and good
centration is obtained with the help of the steep back
optic zone radius (BOZR). The fluorescein pattern
exhibits apical clearance with mid peripheral alignment.
Ideal movement is 1.0 to 1.5mm, with 2mm on
downwards gaze. An increase in the reading add is
achieved by fitting a steeper BOZR. The distance zone,
however, is reduced and this may compromise distance
acuity. For high additions of up to +4.00DS, +2.50 of the
add is generated on the back surface with the remaining
power worked as an aspheric front surface.
By incorporating the asphericity into the back surface,
the profile of the tear film is altered when the patient is
looking down. As the near portion of the lens positions
itself, the pressure of the fitting relationship flattens the
central cornea and creates a steep configuration
inferiorly, where there is a clearance between the cornea
and the contact lens (Hough 2002). In some cases this can
lead to corneal moulding (Figure 11) and, although this
produces no effect on the vision obtained with the contact
lens, may cause spectacle blur in some patients
(Swarbrick et al 2004).
Low-eccentricity designs
• Low-eccentricity designs have a lower range of
posterior flattening
• The BOZR is usually only 0.05–0.10mm steeper than
flattest K
• Low-eccentricity designs require to centre well or
slightly superiorly with an alignment fluorescein
pattern
• Some translation on downwards gaze helps with near
vision

Figure 14. Flow chart for selecting the correction system. RGP, rigid gas-permeable; VA, visual acuity.
Aqualine MF200 (Cantor & Nissel)
This aspheric front surface lens is designed to produce a
progressive power curve which increases from the centre
outwards. This lens is a CD design with an intermediate to
near addition of up to +2.00 within the pupil area. Plus
power is further enhanced in upwards or downwards gaze.
Control of spherical aberration within the power gradient
gives a smooth transition from distance to near vision. The
reading addition cannot work effectively if the lens is
fitted too steep or too flat. Aqualine MF200 is generally
fitted in alignment.
If a higher add is required, the non-dominant eye can be
overplussed by +0.50 but care should be taken not to
overminus distance. For best near vision while reading,
the patient should hold the chin up to use the
intermediate zone.
Pupil size dependency
All the above designs will exhibit variation in performance
depending on the size of pupil. It is barely of significance
in segment, alternating lenses but is most noticeable with
concentric and aspheric simultaneous vision types. Pupil
size varies with light intensity, age and visual task. Even
with careful measurements of pupil size in the consulting
room, there is no guarantee that the lenses will be worn in
similar conditions of illumination in the ‘real world’.
In CN types, low light levels favour distance vision at the
expense of near vision whereas bright sunlight favours
near vision at the expense of distance vision. Thus wearers
of CN concentric bifocals should be advised to wear sun
spectacles when driving in sunlight and be warned that
25
The Correction of Presbyopia with Contact Lenses
there may be difficulties when reading in poor light. The
reverse is true of CD types, where distance vision is best
in bright light and near vision is best in poor light. In
addition there is the advantage that some translation
during inferior gaze will benefit near vision when CD
lenses are used.
AcuVue Bifocal, listed in the literature as a multizone
concentric, is also often referred to as ‘pupil-intelligent’.
The design incorporates five alternating distance and near
rings over an 8mm optic zone (Figure 12). Based on
research of different pupil sizes within the presbyopic
population, the size and spacing of each zone are designed
to optimise vision for various lighting and viewing
conditions. There are four add powers available, which
allows the practitioner to modify the prescription to the
exact individual requirements of the patient. However
near vision is biased with small pupils and distance vision
with larger pupils (Fisher et al 1999, Fonn & Simpson
2003, Morris 2003).
When using aspheric lenses, the same basic factors apply.
In CD lenses with limited addition power, such as the B&L
Occasions lens, the maximum amount of add available is
dependent on pupil size. As the pupil decreases in size, so
the amount of available add decreases. Unfortunately,
pupil size tends to decrease with age so that as more add
is required, less add is available! In CN aspheric designs
such as the Ciba Focus Dailies Progressives and the B&L
Purevision Multifocal, the lens front surface progressively
changes from the centre to the periphery, creating a
gradual power gradient. Aspheric multifocal lenses do not
have a specific add power but a span of power from a preset
near point out to distance, created by the aspheric

C Christie & R Beerton
optics. Distance vision is limited by pupil size, being better
with larger pupils (Kovacich 2006).
The Proclear Multifocal is an amalgamation of spherical
and aspheric optics with unique zone sizes to produce two
complementary but inverse geometry lenses. A CD D lens
is used for the dominant eye and a CN N lens for the nondominant
eye (Figure 13). These lenses are multizonal
with a spherical central area of different sizes for the two
designs, 2.3mm for the distance and 1.7mm for the near.
Surrounding the central zone is a 5mm diameter aspheric
annulus and, surrounding this, a final spherical band
which completes the total optic zone of 8.5mm. Although
this may sound like monovision, each lens is a true
multifocal in its own right and bifocal summation is
maintained. Four specific additions allow the practitioner
to prescribe the distance independently and near powers
for the individual patient’s needs (Kovacich 2006).
Simultaneous multifocals in summary
Alternating or simultaneous vision?
One critical question that should be asked is whether
alternating or simultaneous designs are better (Table 1).
This can be decided based on several variables but visual
requirement is by far the number one. The basic decision
is fairly simple: if good and stable vision is required for
distance and for near, a translating system is the first
method of choice. If flexible and good intermediate vision
is required, simultaneous is the number-one choice
(Benoit 2005, GP Lens Institute 2006, Kovacich 2006,
Lieblein 1996, Norman 2006a).
Diffractive
Diffractive (zone plate) lens designs allow the distance
image to be formed using refractive optics whereas the
near image formation is achieved by central diffractive
‘echelettes’. This lens type is termed ‘pupil-independent’
as the ratio split between distance and near-image
formation is equal regardless of pupil size. Due to the
50/50 split in light there is a correlating drop in contrast
and limited optical performance, especially with higher
additions. Another disadvantage is the build-up of debris
in the prism rings, which are located at the back surface
of the lens. The major positive effect of diffractive bifocals
is that, unlike all other designs, they are pupilindependent.
This diffractive technique was employed on both the soft
Echelon and RGP Diffrax lenses, with limited success.
Neither product is now available (Benoit 2005).
26
Table 1. Comparison between simultaneous and
translating designs
Simultaneous Translating
Age Low additions Higher addition
Pupils > 5mm < 5mm possible
Work Intermediate Distance and
near
Computer 35% > < 35%
Sport Mid-distance Distance and
near
Rx (astigmatism) Limited options Possible
Lens movement Limited movement Must move
Eyelid shape No influence Large influence
Lower-eyelid No influence At or just below
location limbus
Aperture size No influence Large influence
Cost Moderate High
Fitting Challenging More
challenging
Material, Design and Modality
As with single-vision lenses, it is as important, if not more
so, to select a suitable material, replacement frequency
and wearing schedule (modality) for our presbyopic
patients, taking into account their visual and physiological
demands as well as lifestyle.
Examples of contact lenses for the correction of
presbyopia currently available include:
• daily disposables: CIBA Focus Dailies Progressives
• 2-weekly and monthly soft disposables: AcuVue Bifocal;
Coopervision, Proclear Multifocal; Bausch & Lomb,
Soflens 66 Multifocal
• in silicone hydrogel as monthly disposable or 30 days:
CW, B&L, Purevision Multifocal
• planned replacement and conventional soft lenses:
No7, Royal (translating soft (toric available)); Cibasoft
Progressive Toric (simultaneous lens 38% 2hydroxyethyl
methacrylate (HEMA))

In the RGP market, made-to-order makes the list almost
endless. The majority of lenses are available in a range of
materials and Dk, allowing extended-wear options where
required. Key players in the UK market include No7,
Quasar Plus (back-surface aspheric), No7, Quasar
Multifocal (front-surface aspheric), David Thomas,
Essentials (front-surface aspheric S-form technology),
CIBAVision, Astrocon MF (front-surface aspheric),
Menicon, Menifocal Z (concentric), No7 & Scotlens,
PresbyLite2 (translating triangle segment) and No7,
Tangent Streak (translating long line).
The number of presbyopic lens designs available is
constantly growing, thus it is impossible to cover them all in
this text. The ACLM Contact Lens Year Book (Kerr &
Ruston 2006) or website (www.aclm.org.uk) contains a
current and comprehensive list of products currently
available in the UK.
Creative Solutions – More than one Route to
Success
Modified monovision
In this technique, multifocals are used, with the lens
selected for the dominant eye biased for distance vision
(relatively underplussed or overminused) and the nondominant
eye biased for near (relatively overplussed or
underminused). In this way the patient theoretically enjoys
some of the benefits of bifocal lenses with the added
advantages of monovision. This may be essential with backsurface
aspheric lenses of limited reading addition, as the
presbyope requires higher reading additions (Stiegemeier
2006).
Enhanced monovision
In this case, multifocal is incorporated into the monovision
system. To improve (enhance) either distance or near
vision:
• Near: Use a near-biased multifocal in the dominant eye
and a full near-vision-correcting single-vision contact
lens in the non-dominant eye.
• Distance: Use a distance-biased multifocal in the nondominant
eye and a full-distance-vision-correcting
single-vision contact lens in the dominant eye.
• Intermediate: Use an intermediate-biased multifocal in
the non-dominant eye and a full-distance-vision or
slightly overplussed single-vision contact lens in the
dominant eye.
27
The Correction of Presbyopia with Contact Lenses
The technique of enhance monovision may improve the
visual comfort by affording a degree of binocular summation
at the most critical viewing distance (Fischer 1997).
Patient examples
Early presbyope (up to +1.00DS)
• Simultaneous: full correction to both eyes
• Monovision: distance and full near
Mid-presbyope (+1.25DS to +2.00DS)
• Simultaneous: full correction to both eyes
• Translating: full correction to both eyes (do not
overcorrect add)
• Monovision: distance and full near
Late presbyope (+2.25DS to +3.00DS)
• Translating: full correction to both eyes
• Simultaneous: modified monovision; enhanced
monovision
• Monovision: distance and partial near; consider top-up
spectacles to provide additional plus
Establishing patient expectations
Given that all corrections for presbyopia produce some
limitations on visual quality and/or ergonomy, it is critically
important that patients seeking contact lens correction for
presbyopia are made fully aware of the limitations of this
mode of correction. Multifocal lenses may demonstrate lost
lines of distance acuity, reduction in distance and near
stereopsis, and mild to moderate difficulties with night
driving, ghost images and haloes. In some cases auxiliary
spectacles may be a solution to occasional visually
demanding tasks. Patients need to appreciate that there is
no perfect solution to presbyopia and do need to be
counselled in advance, otherwise they often perceive the
outcome as a failure.
Although the ultimate goal is to provide a full binocular
correction at distance and near, it is important to ascertain
from patients whether their priority is good distance vision
or good near vision. This should be determined early on in
the initial consultation.
Remember that, although the practitioner may be obsessed
about the patient achieving 6/6 and N5, the patient is more
interested in visual quality, a function that cannot be
measured using a high-contrast letter chart. It is thus
incumbent on the practitioner to act on patient feedback
following a lens trial than on acuity measurement alone

C Christie & R Beerton
(Fonn & Simpson 2003). However, low-contrast acuity
charts are often a useful way of assessing the ‘real-world’
vision obtained with a presbyopic lens design.
Even with modern and sophisticated lens designs,
monovision still has a higher success rate when compared
to other methods of correcting presbyopia with contact
lenses.
To conclude, the fitting of presbyopes is challenging and
rewarding. The practitioner needs to understand patients’
visual needs and act on their subjective feedback as a
means of refining the correction (Bennett & Luk 2001,
Benoit 2005, Lieblein 1996, Norman 2006 a,b, Van der
Worp 2006).
Clinical Pearls
• Given that all corrections for presbyopia produce some
limitations on visual quality and/or ergonomy, it is
critically important that patients seeking contact lens
correction for presbyopia are made fully aware of the
limitations of this mode of correction.
• Beware of patients who want their vision restored to prepresbyopic
levels!
• Predetermine goals for patients; stress some vision
compromise when used for full-time wear; gain patient
acceptance of goals.
• One of the key factors when fitting the presbyope is to
have some form of clinical strategy:
o If a lens type is to be changed, consider switching
from one basic principle to another and avoid simply
changing to another design that is based on the same
optical principle.
• It is extremely important to be familiar with the
manufacturer’s fitting advice for any one particular
design of lens, as they all differ slightly in design
characteristics and optimal fitting.
• Begin with a binocular vision check. Tell patients: ‘This
lens is designed to work with both eyes open, not one eye
at a time’. If patients are happy with the overall vision at
the initial fitting, don’t try to overrefine it. Tell them that
you want them to try a ‘real-world field test’ and have
them return in a week.
• Always use a trial frame for subjective examination as a
phoropter may influence the pupil size and also make it
more difficult to obtain the reading addition under
normal conditions for near vision.
28
• Alternating lenses are ideal for the rigorous demands of
higher additions, simultaneous for the correction of the
lower. It follows that the add power should be ≥1.00 for
alternators and < 2.00 for the simultaneous candidates.
However, where patients with a high +2.50 add are
prepared to use ‘top-up’ spectacles from time to time,
they may be very happy with the results provided by
simultaneous designs.
• In advanced presbyopia add > 2.00D, pupils tend to be
smaller and alternating vision tends to work better. In
earlier presbyopia, the pupils are larger and
simultaneous designs tend to be indicated.
• Success is generally lower with patients having excellent
uncorrected vision. Given that all contact lens systems
for presbyopia correction impact to a greater or lesser
extent on distance vision quality, it follows that those
patients who are accustomed to relatively good
uncorrected vision may be less able to cope with the
relative impairment in their distance vision. It is
generally better to look for uncorrected vision of 6/9 or
worse. However, this should only be seen as a relative
contraindication and a well-motivated patient can be
surprisingly successful.
• Avoid the temptation to use the phoropter and rely on
flippers. When using flippers, look for an improvement in
overall vision and not an improvement in visual acuity.
• Use the Snellen chart only to record visual acuity for
legal purposes and as a benchmark for future lens
changes.
• At each stage of overrefraction or lens modification, it is
important to record both distance and near acuities to
ensure that an improvement in one does not result in a
trade-off of the other.
• If patients are to be successful they will generally decide
within the first two aftercare appointments. The more
appointments made, the less likely they are to be
successful.
• Success depends on an identification of patients’ visual
needs, skill, refining the correction, a creative approach
to each situation and practitioner enthusiasm (Figure
14). Set realistic patient expectations and don’t be afraid
to change direction or even fail. Success is what is right
for the patient. Remember the 20/happy rule.
• Specialist bifocal and multifocal fitting is a practicebuilding
area that leads to better patient retention and
practice profitability.

References
Bennett ES, Luk B (2001) Rigid gas permeable bifocal contact lenses: an
update. Available online at: www.optometry.co.uk
Benoit DP (2005) Mastering multifocals. Contact Lens Spectrum 7,
28–36
Davis RL (2003) Pinpoint success with GP multifocal lenses. Contact
Lens Spectrum 10, 25–38
De Carle J (1997) Bifocal and multifocal contact lenses. In: Philips AJ,
Speedwell L (eds) Contact Lenses, 4th edn. London: Butterworth-
Heinemann, pp 540–65
Efron N, Morgan P (2006) A decade on: contact lens prescribing trends
in the United Kingdom (1996–2005). Contact Lens Ant Eye 29, 59–68
Fischer K (1999) Presbyopic visual performance with modified
monovision using multifocal soft contact lenses. ICLC 24, 91–100
Fisher K, Bauman E, Schwallie J (1999) Evaluation of two new soft
contact lenses for correction of presbyopia: the focus progressives
multifocal and the AcuVue bifocal. ICLC 26, 92–103
Fonn D, Simpson T (2003) Successful monovision contact lens wearers
refitted with bifocal contact lenses. Eye Contact Lens 29, 181–4
Ghormley N (2003) New bifocal designs in hyper-oxygen materials. Eye
Contact Lens: Sci Clin Pract 29 (Suppl. 1), 180–1
GP Lens Institute (2006) Correcting presbyopia. Available online at:
www.gpli.info/correcting-presbyopia-04
Multiple Choice Questions
29
The Correction of Presbyopia with Contact Lenses
Hough A (2002) Soft bifocal contact lenses: the limits of performance.
Contact Lens Ant Eye 25, 161–75
Kerr C, Ruston D (2006) The ACLM Contact Lens Year Book.
Association of Contact Lens Manufacturers, Devizes
Kovacich S (2006) Know your soft bifocal lens options. Contact Lens
Spectrum 5, 33–45
Lakkis C, Goldenberg S, Woods CA (2005) Investigation of performance
of the Menifocal Z gas-permeable bifocal contact lens during continuous
wear. Optom Vis Sci 82, 1022–9
Lieblein J (1996) Multifocal phobia? Try this 5-step program. Contact
Lens Spectrum 8, 23–8
Morris J (2003) The ageing eye, contact lenses for the over-40s. Optom
Today 2, 24–30
Norman C (2006a) Patient selection tips for presbyopic GP lenses.
Contact Lens Spectrum 5, 17
Norman C (2006b) Silicone hydrogel lenses and the presbyope. Contact
Lens Spectrum special edition, 8–9
Stiegemeier MJ (2006) Prescribing for presbyopia. Contact Lens
Spectrum 3, 9
Swarbrick H, Hiew R, Kee Ai Vy, Petersen S, Tahnan N (2004) Apical
clearance rigid contact lenses induce corneal steepening. Optom Vis Sci
81, 427–35
Van der Worp E (2006) The art of GP contact lens fitting for
presbyopia. Boston Update 18, 1–4
This paper is reference C-5148. Two contact lens related credits are available. Please use the inserted answer sheet. Copies can be obtained
from Optometry in Practice Administration, PO Box 6, Skelmersdale, Lancashire WN8 9FW. There is only one correct answer for each
question.
1. When determining ocular dominance, why is fogging
of more value than sighting techniques?
(a) It is quicker to carry out
(b) Fogging measures the ability of a patient to suppress
an out-of-focus image
(c) It is easier to do while viewing a distant object
(d) Sighting dominance tests are unable to measure
dominance
2. Partial monovision is ideal for:
(a) Emerging (early) presbyopes
(b) Amblyopes
(c) Where full monovision correction has failed
(d) Existing multifocal wearers who require a stronger
reading addition
3. Which of the following best describes alternatingvision
lenses?
(a) Both distance and near portions are positioned before
the pupil at any time
(b) Lens movement will bias distance or near sections in
front of the pupil
(c) Inlaid etching allows diffraction to produce a second
image from a different distance
(d) One eye is fitted with a single-vision lens, the other a
multifocal
4. Which of the following lens designs is not a translating
design?
(a) PresbyLite 2
(b) Royal
(c) Tangent Streak
(d) Diffrax
5. Which of the following best describes simultaneous
vision lenses?
(a) Both distance and near portions are positioned before
the pupil at any time
(b) Lens movement will bias distance or near sections in
front of the pupil
(c) Inlaid etching allows diffraction to produce a second
image from a different distance
(d) One eye is fitted with a single-vision lens, the other a
multifocal

C Christie & R Beerton
6. Which of the following lens designs is not a
simultaneous vision design?
(a) Focus Dailies Progressive
(b) Proclear Multifocal
(c) Purevision Multifocal
(d) Echelon
7. Why is the AcuVue Bifocal sometimes referred to as
being pupil size-independent?
(a) The lens can move in front of the pupil without
causing near-vision difficulties
(b) The size and spacing of each zone are designed to
optimise vision for various lighting and viewing
conditions
(c) Irrespective of the pupil size, the lenses are always
biased towards near vision
(d) The optic zone can be made in different sizes to
match the average pupil size
8. Which of the following statement is false?
(a) Pupil size varies due to ambient lighting conditions
(b) Pupil size varies due to age
(c) Pupil size varies due to gender
(d) Pupil size varies due to visual task
9. Regarding presbyopic correction with contact lenses,
which of the following statements is false?
(a) You should always familiarise yourself with the
manufacturer’s fitting advice
(b) Alternating lenses are better with higher additions
(c) Advise patients that pre-presbyopic levels of vision
are difficult to obtain
(d) A phoropter is ideal for over-refraction of
simultaneous design lenses
30
10. Which of the following statements is true?
(a) Using Snellen acuity charts is the most accurate
means of measuring vision with multifocal lenses
(b) Pupil size is unaffected when using a phoropter
(c) A translating lens must move freely upwards on
downwards gaze
(d) Increased minus power aids near vision
11. Which of the following methods is most successful for
fitting presbyopic contact lens patients?
(a) Monovision
(b) Modified distance vision
(c) Simultaneous multifocals
(d) Alternating bifocals
12. Which of the following best describes enhanced
monovision?
(a) Both distance and near portions are positioned before
the pupil at any time
(b) Lens movement will bias distance or near sections in
front of the pupil
(c) Inlaid etching allows diffraction to produce a second
image from a different distance
(d) One eye is fitted with a single-vision lens, the other a
multifocal

Optometry in Practice Vol 8 (2007) 31–34
A Case Report Demonstrating the Use of
Customised Reduced-Aperture Spectacles in
a Patient with Retinitis Pigmentosa
Rasmeet K Chadha, 1 BSc (Hons) MCOptom Vanita Sachdev BSc (Hons) MCOptom
and Joanne C Steen BSc (Hons) PhD MCOptom
Optometry Department, Oxford Eye Hospital, Woodstock Road, Oxford OX2 6HE
Date of acceptance 26 September 2006
Introduction
Glare is a sense of excessive brightness within the visual
field causing discomfort (discomfort glare) and/or reduced
visual performance (disability glare) (Millodot 1993).
Clinical experience suggests that patients often
experience both forms of glare simultaneously.
An essential part of low-vision rehabilitation is the
management of glare and tinted lenses are often
prescribed for this purpose (Eperjesi et al. 2002). Other
solutions typically used by the low-vision practitioner
include modification of the environment, side shields,
typoscopes and hats with brims. These solutions often
lead to significant subjective relief of symptoms; however,
few studies have been able to corroborate these subjective
findings definitively with clinical measures of visual
performance (Wolffsohn et al. 2002).
This article describes the design and effectiveness of a
novel aid for the management of disability and discomfort
glare.
Case History
A 55-year-old male (DH) with advanced autosomalrecessive
retinitis pigmentosa (RP) had been seen at
Oxford Eye Hospital since 2000. He experienced
significant discomfort and disability glare every day. In
particular the glare induced by light reflected from white
paper posed a major limitation on his ability to work as a
company director.
Best corrected distance and near visual acuity (VA) were:
Distance R) –2.00/–0.50 × 90 6/12 L) POL
Near R) ADD +2.50 N6 L) POL
His residual static visual field was < 10º when tested on a
Humphrey field analyser.
© 2007 The College of Optometrists
31
His consultant was not prepared to consider cataract
surgery for his mild posterior subcapsular lens opacities
(PSCLO) as it is well known that patients with RP suffer
from glare irrespective of whether they have significant
PSCLO. In a group of patients with RP with either no or
trace PSCLO, Alexander et al. (1996) demonstrated a
significant inverse correlation between intraocular
straylight and residual visual field. Extrapolating their
results to this case would suggest that DH had straylight
levels that were approximately three times that of agematched
norms.
Various methods of glare management had been tried
previously. These included:
• Typoscope: of limited success due to restriction in the
amount of visible text
• Tinted spectacles (approximately 50% light
transmission factor for indoor use): the most
successful of all strategies tried. Photochromic lenses
were of limited value, as supported by Silver & Lyness
(1985)
• Tinted overlay: discussed with DH but of limited use
due to the number of sources of reading material in use
simultaneously, therefore requiring multiple overlays
• Visors/side shields: Steen et al. (1993) reported that
methods to reduce peripheral glare sources are the
most successful way of managing disability glare.
Certainly side shields and visors helped to reduce
peripheral extraneous glare for DH when used with
fixed tinted spectacles but did not eliminate the glare
symptoms completely
Novel solution
A pinhole is well known to improve visual acuity by
decreasing light scatter and improving contrast in cases of
central corneal scar or significant lens opacity. We
therefore considered whether this could be extended to
patients with RP. However, a standard pinhole (1.5mm)
would only allow a rotating eye field of 3.2º. Indeed, DH
found this encroached on his working visual field.
Address for correspondence: RK Chadha, Optometry Department, Oxford Eye Hospital, West Wing (LG1), John Radcliffe Hospital, Headley
Way, Oxford OX3 9DU, UK.