Any evidence of dissolving cataracts successfully?
I can think of lots of ways to successfully dissolve cataracts. They’d all probably kill you, though.
Well, if you want to keep the rest of your cornea. . .
Cataracts are a clouding of the lens. The lens is inside your eye, behind the cornea. I don’t know of a substance that can penetrate the cornea or sclera without damaging it but while “affecting” the lens. I also am not sure that “cataracts” are a discrete structure that can be disambiguated from the lens.
Cataracts can be burned off, that is burned off artificial lenses. Once you’ve had cataract surgery and had the lenses replaced, you have about a 30% chance of what they call “secondary catartacts”. Those can be removed by laser treatment.
If you squint hard enough, you can call that melting or even dissolving.
Posterior capsule opasification (pardon my spelling) is when the back of the lens capsule, now holding the replacement lens, turns cloudy. A YAG laser is used to burn a small hole thereby allowing clear vision again. I’ve had it done with both eyes.
Anything you put in your eye, or a secretion that your eye makes naturally, that could theoretically dissolve a cataract would do the same to your cornea.
With a laser or bladed scalpel, the surgeon aims for the cloudy part of the cornea explicitly.
Medicines that can do what you are asking for are theoretically possible*, just decades to centuries beyond present tech. At the molecular level, cataract tissue is different from cornea tissue. So if you could build some kind of molecular mechanism that senses the structure of what it is touching and can tell the difference between the tissue types, it could limit the damage to only the cataract regions. Some kind of genetically engineered organism or nanoscale robot could do that.
*Human immune cells can tell the difference between your cells and those from another human, which is about as fine grained a distinction as what you are asking for. So it is possible.