You can touch the top of the can to tell where it is, and when you get ready to turn the egg, slide a spatula under the bottom of the can, and pick the egg up. It will be perfectly formed, and you can turn it without difficulty. I understand that blind persons are not the only ones who sometimes have trouble turning the eggs they are frying. Some sighted persons have the same difficulty. The tuna can works just fine, and there isn't any point in wasting money or going to extra trouble.
Some commercial gadgets are really an advantage in cooking.
Earlier, I mentioned rice. My wife is sighted, and I am blind, but we both use and like the rice-cooker. You put twice as much water as rice into it, and you turn it on. You don't do anything else. That rice-cooker also knows other things, and it has a mind of its own.