What are clear, fluid-filled sacs/"bubbles" inside the eye called?

Do you mean on the inside of the eyelids? Little seed-type jobs? They sound like budding styes. If it's more than one or two, and they don't go quickly by themselves, see your doctor because you might need some drops. You can also get 'goldeneye' ointment, the old-fashioned remedy, but personally I wouldn't bother. Try not to rub or scratch at them, and don't burst them. Whenever I've had them (once or twice) they've gone by themselves, but I do know someone who's had a heap of trouble - not worth taking any chances if you're at all worried.

It sounds like a cyst. Make an appointment with an ophthalmologist to make sure that's all it is.

I don't know but I would see your doctor about it...