Could an existing drug restore color vision in rare blindness?

This early-phase study tests whether glycerol phenylbutyrate (PBA), a drug already approved for other conditions, can improve vision in people with a rare inherited form of color blindness (achromatopsia) caused by ATF6 gene mutations. Two adults with the condition will take PBA three times daily and undergo several eye tests over three clinic visits. The goal is to see if the drug can reduce stress in the retina and improve color vision and other visual functions.