My pet suddenly keeps one eye squeezed shut — can a scratched eye wait a day?
An eye held shut with tearing usually means the cornea is damaged — and a scratch can deepen into an ulcer or perforate fast, so it belongs at a hospital the same day.
The cornea is only about half a millimeter thick, and pain receptors are packed into its surface — which is why animals squint hard, tear, and paw at an injured eye. The same signs also cover glaucoma and foreign bodies under the lid, none of which can be told apart at home.
Why waiting and old eye drops both backfire
A surface scratch can deepen within a day or two, especially in flat-faced breeds whose prominent eyes dry quickly, and an infected ulcer can melt through the cornea. Rubbing accelerates all of it, so fit an e-collar if you have one. Do not instill leftover eye drops: steroid-containing drops make a corneal ulcer dramatically worse, and without staining the eye no one can tell which injury they are treating.
How fast an eye deteriorates varies by breed, tear production, and the individual animal, and vision lost to a perforated or scarred cornea is hard to win back. An eye held shut, clouding, bleeding, or bulging is a same-day problem at the latest — see a veterinarian promptly, and immediately if the eye changes shape or the pet is in obvious pain.
MediIndex articles are for general information only and are not medical advice, diagnosis, or advertising. Outcomes vary by individual — consult a board-certified specialist for personal decisions.