In several single-center trials, topical Cysteamine therapy has been proven effective in dissolving corneal crystals in cystinosis patients, but its use is difficult because it oxidizes at room temperature and must be dispensed frozen to the patient. The results of two randomized (eyes) clinical trials assessing the safety in one trial (single center) and efficacy (multicenter) in a second trial of cysteamine eye drops versus a new drug preparation, more stable at room temperature, has been completed. Although no serious adverse reactions were observed with either formulation, the new formulation was not as effective as the standard formulation in reducing corneal crystals in cystinosis patients as measured by masked assessment of the corneal crystals using anterior segment photography.