A cat with an ear infection can experience discomfort and discharge from the infected ear. An ear infection can lead to serious complications that can affect a cat's balance or its eyes.
Horner's syndrome is a neurological condition. A cat with Horner's syndrome will have one eye with a smaller pupil and a drooping upper lid. The third eyelid of that same eye will protrude and the eye could appear sunken, according to "Cat Owner's Home Veterinary Handbook."
A cat experiences an ear infection when bacteria or fungus grows within the ear, causing itching, inflammation and discharge.
An ear infection can occur when water or grass lodges in a cat's ear. According to the University of Sydney, a severe ear infection can cause damage to the nerves that affect a cat's eye, leading to Horner's syndrome.
An ear infection can be treated by cleaning a cat's ear with eardrops. Oral medication could be needed for severe infections. Horner's syndrome might resolve over time. Antiinflammatory medications can help a cat heal.
"The First+Aid Companion for Dogs & Cats" states that keeping a cat's ears clean and dry can prevent ear infections from beginning or from becoming serious.