The primary purpose of this study is to evaluate the safety and efficacy of a new formulation of cysteamine eye drops to treat children and adults with cystinosis and cystine crystal accumulation in the cornea. The safety of this new formulation will be evaluated among 30 children and adults with a history of cystinosis under treatment at the NIH with the current preparation of cysteamine eye drops. Patients will be randomized to the current preparation in one eye and the new formulation in the other eye. Vision, blurring, redness, pain, irritation, and itching will be evaluated in each eye at Week 1, Week 2, Week 4, and Month 6. Complete ophthalmic evaluation including corneal slit lamp examination with photographs will be performed at baseline and 6 months at the NEI Clinical Center.