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Around 6 months ago my best C. Schultzei developed a case of cloudy eye after a long stretch of spawning. I seperated her and treated with Melafix/Pimafix, then gave her a long period of rest and relaxation in a nice 75g display tank and while she never appeared sickly her eyes didn't recover.
She used to spawn at the drop of a hat, now while others are spawning around her, she just sits. She's only 18 mths old.
Any suggestions as to how I could possibly save her eyes would be greatly appreciated. (play sand, 77°F, 0 amm, 0 nitrite, 10 nitrate, 6.6 pH, 2GH, tank mates: glowlight tetras, similis corys, 12 black corys, L177)

Such damage or disease to a fishes eyes is not something any medication can cure.
Minor scratches will heal on their own most of the time but in those cases the eyes clear up within 7 to 10 days.
Any problem that persists longer than that is normally permanent. You can achieve just as good results by adding several Cattapa leaves.
Melafix and Pimafix are not really very effective at treating any fish diseases.
When they seem to work the odds are high that the condition would have resolved itself with no treatment at all.
These two meds are akin to the holistic medical treatments where the placebo effect is what is behind most of the positive out comes. Fish lack the higher brain functions of humans so there can be no placebo effect.

This fish may have some kind of internal parasitic worm infestation. I would try a combination of flubendazole, praziquantal and metroniadazole to help eliminate most internal parasites. These may be used together. I would treat her in a 5 gal quarantine tank.
If they work on what ails your Corydoras they will not restore the damaged eye but they may get her healthy enough to be used for breeding again but it is a fact that not every sick fish can be saved even when the most effective of drugs are used. One bad eye will not interfere with her ability to spawn as long as she is otherwise healthy.

I have had similar problems occur among large Discus which injure an eye when they are panicked and most of the time the damage heals by itself but in severe cases it is permanent.