Isathal is the new name for Fucithalmic....
The eye dye will show up any scratches or damage to the surface, so you're lucky....
Easiest way to put eye drops in is to do it while the dogs laid down. Let him close his eye, as he will instinctively do, and then lift the upper lid and just squeeze the lotion into it. You don't need to go mad, literally a couple of drops will do. maybe give him a treat afterwards and tell him he's a good boy and all that stuff.
JMHO....
alternatively, sit on the twat and bang it in