Ocular clinical signs are essentially represented by:

Congenital nystagmus
It is often pendular or horizontal, with a blocking position in which the vision is better. It can result in a consistent stiff neck.
It can be accompanied sometimes by a nystagmus of the head. It may be associated with astigmatism, farsightedness and nearsightedness.

Photophobia
Proportional to the hypopigmentation of the iris. It can be very debilitating with the child's head preferentially flexed or it can occur only in very sunny surroundings.

Strabismus
Can be stimulated by an abnormal decussation of the optic fibers.

Visual impairment
It can be deep with visual impairment from a distance reduced to 1/ 20 but more often it's mild with visual acuity of 2/ 10. Visual acuity can reached 5-6/ 10 and be compatible with driving.
There are no abnormalities in the visual field.