Today I have by accident thrown a AAA battery into a bucket of water. I fished it out of the water immediately (within 20 seconds or so) and nothing notable had happened and the battery is still full according to a battery test device.
Cats Scratching Ears with Parasites. If this is not the issue, then it may be related to parasites alone. Check your cat's ears for signs of ticks, fleas, and mites. These parasites can cause obsessive scratching, as the cat makes a desperate effort to relieve pain and discomfort. If your cat is not allergic, try using natural tick or flea repellents (or mite repellent) if that seems to be the issue.
Corneal scratch: When a cat's eye surface is scratched, a cat will feel pain, will rub the eye, squint and not tolerate the light. Such scratches may be caused by eyelashes rubbing against the cornea or foreign bodies stuck in the eye. Should a mild scratch occur, it usually would heal itself within 24 to 48 hours.