Poor Sight and Sore Eyes in Chickens
Chickens have extremely good daytime vision. In fact, chickens rely on their sense of sight more than other senses to conduct their daily business. Flock keepers notice quickly when chickens have impaired vision and aren’t able to cope with finding food, navigating the coop, or avoiding bullies.
That’s when they take a closer look at the chicken’s eyes, and find . . . What is that? You may find it difficult to describe an eye problem or identify the part of the eye that’s affected, due to unfamiliarity with the anatomy.
Potential eye problems
The figure shows parts of the eye to help you get your bearings.
Eyelids: A chicken’s eye has three eyelids — upper, lower, and the third eyelid.
Fowl pox, a viral infection, causes scabby eyelids.
Conjunctiva: This is the moist, pink tissue around the eye. Inflammation of this tissue is known as conjunctivitis, or pink eye.
Small stuff (foreign bodies) like seeds or grit can get stuck in the conjunctiva.
Conjunctivitis usually goes along with respiratory infections.
Eyeworms cause swollen conjunctiva in chickens living in the tropics and possibly in warmer areas of the United States.
Cornea: This is the transparent front part of the eye that covers the iris and the pupil. An injured cornea is very painful, so the chicken will hold the eye shut. A damaged cornea may become cloudy. If you find it difficult to see the iris or the pupil through a cloudy eye, the cornea is mostly likely the location of the problem.
A cloudy cornea may be the result of an injury or an infection with bacteria, a virus, or a fungus. Ammonia fumes from dirty, wet litter can injure the cornea. Cloudy corneas can get better, or turn into permanent scars.
Iris: It’s the colored part of the eye, which is commonly reddish brown in chickens. The irises of both eyes should be the same color. Here’s a strange, but commonly seen iris defect:
An iris that turns gray (called gray eye) is a sign of Marek’s disease.
Pupil: The pupil is the round dark spot in the center of the eye that lets light through to the back of the eye. The pupil should be round, have distinct (not blurry) edges, and get smaller if you shine a light on the eye. The following are not-quite-right chicken pupils:
An irregularly shaped (not round) pupil is a sign of Marek’s disease.
A white spot or cloudy look to the pupil may be a cataract, which is often the result of avian encephalomyelitis infection as a chick, vitamin A deficiency, old age, or genetics.
Get treatment for eye issues
A veterinary ophthalmologist, a specialist who does nothing but look at animal eyes all day, is the go-to person for state-of-the-art care of a troublesome eye problem in a pet chicken. You won’t find an eye vet in most towns, but any small animal veterinarian will be able to refer you to the closest veterinary ophthalmologist.
Here are some simple treatment options if you identify minor issues:
Conjunctiva: If your hen has something in her eye, you can flush out the gunky eye with an eye wash, which may help dislodge a foreign body.
Cornea: In the early stages of a cornea injury, applying an antibiotic ointment to the affected eye twice daily may be helpful. A do-it-yourselfer can purchase tetracycline ophthalmic ointment at pet or farm supply stores or online.
Iris: No treatment is available for Marek’s disease and gray eye.
Pupil: Irregular pupils and cataracts also don’t have any treatment.
Poor vision due to swelling of the eyelid, conjunctiva, or cornea can get better as the swelling subsides. Blindness due to Marek’s disease, cataracts, or scarred corneas is permanent. A chicken blind in one eye often does well with the handicap.