The problems with vision "result from abnormal development of the retina and abnormal patterns of nerve connections between the eye and the brain." These problems consist of :
- Regular eye movements back and forth.
- Cross eyes or lazy eye caused by muscle imbalances.
- Sensitivity to light because the iris has little to no pigment to screen out stray light.
- Astigmatism along with either near-sightedness or far-sightedness.
- Foveal hypoplasia caused by the abnormal development of the fovea before birth and in infancy.