MANUAL PHYSIOLOGY PRACTICAL - Repository:The Medical ...

FM/UOJ
Light reflex:
Ask the subject to fix the gaze on a distant object. Inspect the iris and identify the
pupil of both eyes. Take a touch and shine it into one eye from one side, avoiding the
visual attention on the torch. Observe constriction of the pupils of both eyes. Repeat the
test with the other eye. As an alternative, observe the size of the pupil of one eye
and then cover the other eye suddenly and observe the change in the size of the pupil.
Exercise: trace the pathway and describe the findings in possible lesions:
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Near Response:
The subject fist fixes the gaze on a far object while the examiner holds a
illuminated object in front of the subject about 50 cm. away. The subject is then asked to
look at the near object. Three important changes occur: convergence, pupillary
constriction and accommodation. Convergence and pupillary constriction are easy to
observe. Accommodation is difficult to observe. The images formed by reflection on the
different surfaces are used to indicate accommodation.
When the subject is looking into distance and the object is held in front of the
subject 3 reflections are seen: a clear, small upright image reflected from the cornea; a
larger fainter upright image reflected from the anterior surface of the lens; and a small
inverted image reflected from the posterior surface of the lens. Identify these images
before asking the subject to look at the object and keep on observing the images while the
subject does so. The first image does not change. The second image becomes smaller and
moves towards the third image. The third image change very little.
Eye Muscles
The muscles of the eye keep both eyes focused on the same object at all times.
This is shown by the position of the cornea. If the eyes are not parallel, it indicates
presence of squint as a result of weakness or paralysis of one or more of the eye muscles.
This is further tested by moving a finger in front of the patient towards up, down,
right, and left. Defects in the movement of any eye indicate paralysis or paresis of the
muscle.
Neurology
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