[abousoun]

This is a simple case of Cyclopia which is :
"An abnormality characterized by the development of a single eye, located in the area normally occupied by the root of the nose, and a missing nose or a nose in the form of a proboscis (a tubular appendage) located above the eye" ... as clearly shown in the picture above

There is also Anopthalmia which is complete absence of both eyes

and concerning "أعور الدجال" he has 2 eyes not a single one, like the above text trying to desribe ...
and most of the talks say that his right eye is the blind one and the left one is defective as well (a lot of debates concerning this issue)

Thank You ...