age of onset between 6 months and 4 years(usually at 18 months)
occasionally then one eye divergens patient close this eye in bright light
sometimes diplopia occurs
once suppression has been triggered by the eye drifting out
patients have a larger binocular peripheral visual field than normal people
typical cases have stereoacuity at near, this is where most patients control their deviation
assessment of vision, fusion and stereopsis
Hirschberg test at near and distance (Fig7,8)
cover-uncover test at near and distance
high AC/A can be diagnosed by the patch test
deprivation (sensory) exotropia
cosmetic success is often defined as a deviation less than 15PD
functional success is than a deviation less than 10PD with peripheral fusion
some patients may miss the panoramic visual field inherent in intermittent exotropia
Convergence weakness is a type of exotropia in which the deviation is only or greater at near than at distance.Fig.9.10.
Fig.9 Convergens insufficiency. Small exotropia in the distance.
Fig.10 Convergens insufficiency when child looking at near point the exotropia appears.