TL;DR: Squinting and light sensitivity in cats are signs of ocular pain that require a veterinary exam within 12 to 24 hours to prevent permanent blindness. Seek immediate emergency care if the eye appears enlarged, changes color, or has a visible puncture.
What are blepharospasm and photophobia in cats?
When a cat squints or keeps their eyes shut, it is medically known as blepharospasm. This is typically a sign of pain rather than just a tired eye. Avoiding light, or photophobia, often occurs alongside squinting because light exposure can trigger sharp pain if the cornea is damaged or if there is internal inflammation. These symptoms indicate that the eye's protective mechanisms are working overtime to shield the eye from further irritation.
Is my cat squinting a veterinary emergency?
- The urgency level for a squinting cat is Medium; eye issues are considered "functional emergencies" because they can progress to permanent blindness very quickly.
- You should aim to have your cat seen by a veterinarian within 12 to 24 hours.
- Seek immediate emergency care if the eye looks enlarged, has changed color, or if there is a visible puncture.
How can taking a photo of my cat's eye help during triage?
- A clear photo allows the professional to see the exact degree of squinting and whether the third eyelid is elevated.
- Photos help identify the color of any discharge (clear, yellow, or green).
- This visual data helps differentiate between a mild infection and a serious corneal ulcer, ensuring your cat receives the correct priority for treatment.
Clinical Context (Merck Veterinary Manual)
In cats, squinting (blepharospasm) and light avoidance (photophobia) can indicate ophthalmic emergencies. Systemic diseases frequently affect the eye and associated structures; eyelid inflammations are often associated with systemic Demodex cati and D gatoi, Notoedres cati (scabies), ringworm, and immune-mediated skin diseases. Common infectious pathogens, such as feline herpesvirus-1, Chlamydia, and Mycoplasma, frequently present as acute and recurrent conjunctivitis. Feline herpesvirus-1 is also associated with ulcerative and stromal keratitis, proliferative keratoconjunctivitis, corneal sequestrum, corneal symblepharon, and keratoconjunctivitis sicca. Feline infectious peritonitis, toxoplasmosis, feline immunodeficiency virus, and feline leukemia virus often present as anterior and posterior uveitis, chronic uveitis, retinal detachment, and secondary glaucoma. Acute vision loss may also occur with intraocular hemorrhage and retinal detachment.
Chapter: Ophthalmology, Emergency
Source: The Merck Veterinary Manual, 11th Edition (Page 1696)