Though variety of ocular abnormalities might be present in several hereditary diseases some findings are essential for making the diagnosis.
Cystinosis is accompanied by photophobia that results from corneal cystin deposits. Later in life, retinal blindeness may occur in some cases.
The copper-colored ring at the periphery of the cornea, the Kayser-Fleischer ring, is pathognomonic of Wilson disease.
Update: April 29, 2019