MANUAL PHYSIOLOGY PRACTICAL - Repository:The Medical ...

FM/UOJ
Experiment N2
EXAMINATION OF THE EYE
Eye is a special sense organ and its functions involve perception of light, image
formation and transmission of impulses. The function is further carried out in the occipital
cortex, association areas and finally in the Wernicke’s area. These functions are
facilitated by the eye muscles supplied by somatic nerves and cornea and ciliary body
supplied by autonomic nerves. Complete examination of the eye, therefore, comprises
several different procedures.
Experiment 2.1
Visual illusions.
Several pictures are displayed for observation. Observe each picture from a
distance and then read the notes given about the picture. This will help you to understand
that vision is not just image formation but also interpretation in the cortex.
Experiment 2.2
Field of Vision
Gross abnormalities of the field of vision can be detected by clinical examination.
Perimeter is used to map the field of vision accurately.
Clinical Examination for Field of Vision.
This is based on comparing the field of vision of the examiner with that of the
subject, one eye at a time. The subject is seated in front of the examiner at about two feet,
eyes of both at the same level. The subject covers that left eye and the examiner covers
the right eye. Both fix the gaze of the uncovered eye on the other’s eye. The subject is
instructed to keep the eye fixed on the examiner’s and to indicate when the moving finger
of the examiner comes into view. The examiner moves the finger in the plane between the
two. First the finger is raised up above the visual area and lowered slowly: when the
subject reports of seeing the finger, the examiner will be able to judge the subjects upper
quarter of the visual field by comparing with the personal perception. Similarly the finger
is moved from nasal, inferior and temporal areas and the field of vision is tested. The
procedure is repeated with the other eye.
Perimetry:
Instrument:
Perimeter is used to record the field of vision. One eye is tested at a time. A
stand is provided to fix the chin and a white mark is placed in the instrument to fix the
gaze. The height of the stand could be adjusted so that the tested eye is placed at the level
of the mark.
Neurology
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