for OD students by kausar ali .

3. Anisokonia :
 Anomalies of binocular vision .
 Ocular images are unequal in size or shape or both .
 Its important lies in case of eye strain which is difficult
to assess .
 Etiology:
 Optical anisokonia
 Retinal anisokonia
 Cortical anisokonia

4.  Optical anisokonia :
inherited .
Acquired .
Anisometropia of high degree .
 Retinal Anisokonia :
Displacement of retinal
image towards nodal point
in one eye .
 Cortical Anisokonia :
A symmetrical simultaneous
perception in spite of equal size
of two images .

5. Clinical types:
 Spherical :
 Image may be magnified or minified equally in both
merida .
 Cylindrical:
 Image is magnified of minified symmetrical in one
meridia .
 A symmetrical :
 Prismatic .
 Image difference increases progressively in one
direction

6.  Pincushion:
 Image distortion increases progressively in both direction
as seen with high plus correction in aphakia .
 Barrel .
 Image distortion decreases progressively in both direction
as seen in high minus lenses .
 Oblique :
 Image size remain the same but there occurs oblique
distortion of shape .

7. Symptoms :
 Asthenopic symptoms :
 Occurs when the difference in image size of the two
images between 0.75 to 5%
 Headache , difficulty in reading , photophobia ,
difficulty in fixation , vertigo etc .
 Disturbance of binocular vision .
 Diplopia occur only if the difference exceeds 5%.
 Disturbance in the depth perception and spatial dis –
orientation.
 Suppression of one eye

8. Treatment
 Optical < IOL in Aphakia.
contact lenses.
Refractive surgery.
 Retinal Anisokonia :
corrected by treating the causative disease.
 Cortical Anisokonia :
Difficult to treat .