risk is inherent in this sport, if you feel you can mitigate the risk of deteriorating vision I would encourage you to keep jumping, don't give up because genetics dealt you a bad hand, now that being said under canopy at high traffic dz's such as eloy this could be a greater risk to yourself and other jumpers, you might want to find a cessna club or dz and keep the risk of canopy collision to a minimum, if there are only 3 other jumpers in the air with you they can all be aware of your handicap and adjust procedures easily to help you out, and maybe find the closer jump crew who can help you deal with what you are going through as a good sky family does, oh yeah and double up on audibles haha, i'd still jump with you, and i hope you find a treatment that helps nip this in the ass.