This causes a lack of oxygen to the retina and can lead to blindness within minutes. Other problems found in the Shih Tzu include eyelash disease, which consists basically of two conditions. These are the eyelashes abnormally located at the eyelid margin which may cause ocular irritation. Distichiasis may occur at any time in the dog's life. The hereditary basis of the condition is not established.
Second condition is ectopia cilia.
Ectopic cilia is like distichiasis in the fact that ectopic cilia are eyelashes that instead of emerging from the eyelid margin, the hairs emerge through the eyelid conjunctiva. They most commonly occur in the upper central eyelid. These are found in younger dogs and can cause significant pain as exhibited by squinting and facial wetness. Like distichiasis, corneal ulcers can occur. This is unlike the breeding recommendation in the previous conditions that were described, where the breeding advice is breeder option.