What your tomato frog has is nose/eye rub. It has rubbed against the sides of it's enclosure that the friction has worn away part of the eye lids and nose. It will heal over but it will be permanently scared / discolored on the nose and the eye lids, which will never grow back, so the top of the eyeball will always be exposed. They can be fat and lazy and sit there for days, weeks, months on end but sometimes they do get very active and will jump around and rub their face into the side of the enclosure as they don't understand the invisible barrier that's stopping them. The exact same thing happened to one of mine but not as bad as yours. If I see her being energetic I usually feed her a lot of food to get her to settle down lol.