First, as I understand it, photostimulation was developed more than 80 years ago in Europe to treat certain amblyopia. People are still doing it in China. But in the US, no one is doing it, because occlusion/patching is the treatment of choice. Second, light is considered by some to be accelerator of retinal dystrophy. Phototoxicity likely plays a role in retinal degeneration caused by rhodopsin mutations. However there is no direct evidence demonstrating that light is a modifier of RP. It is still prudent to protect from high level of light exposure. Therefore, I would advise patching the good eye rather than using photostimulation to treat amblyopia if the patient is still within the critical time for treatment, usually before age 7 ( it can be extended to early teens.)
To correct amblyopia, the treatment of choice is to cover the good eye to force the use of the weak eye for a period of time. If necessary, the child should also be fitted with the correct glasses or to have strabismus or other surgery to help improve the condition of the weak eye.