Asteroid hyalosis
Asteroid hyalosis is a degenerative condition of the eye involving small white opacities in the vitreous humor. The cause is unknown.

Cataracts
Cataracts are an opacity in the lens of the eye. Most cataracts in dogs are caused by a genetic predisposition, but diabetes mellitus is also a common cause. The only effective treatment is surgical removal.

Chalazion
Chalazion is a granuloma that forms in the eyelid due to blocked secretions from the Meibomian gland. Inflammation of the eyelid may result.

Cherry eye
Cherry eye is the term used to refer to canine nictitans gland prolapse, a common eye condition in various dog breeds where the gland of the third eyelid prolapses and becomes visible.

Collie eye anomaly
Collie eye anomaly (CEA) is a congenital, inherited, bilateral eye disease of dogs involving the retina, choroid, and sclera. It can be a mild disease or cause blindness. It is known to occur in Smooth and Rough Collies, Shetland Sheepdogs, Australian Shepherds, Border Collies, and Nova Scotia Duck Tolling Retrievers.

Conjunctivitis
Conjunctivitis is inflammation of the conjunctiva. In dogs it is most commonly caused by mechanical irritation (such as by entropion, ectropion, or trichiasis), allergies, and keratoconjunctivitis sicca. Any bacterial infection is usually secondary.

Corneal dystrophy
Corneal dystrophy is a condition characterized by bilateral, noninflammatory opacity of the cornea. It appears as grayish white lines, circles, or clouding of the cornea. Corneal dystrophy can also have a crystalline appearance.

Corneal ulcer
Corneal ulcer, or ulcerative keratitis, is an inflammatory condition of the cornea involving loss of its outer layer. They are caused by trauma, detergent burns, and infections. Other eye conditions can cause corneal ulcers, such as entropion, distichia, corneal dystrophy, and keratoconjunctivitis sicca.

Distichia
Distichia (including ectopic cilia) is an eyelash that arises from an abnormal spot on the eyelid. Distichiae usually cause no symptoms because the lashes are soft, but they can irritate the eye and cause tearing, squinting, inflammation, and corneal ulcers.

Ectropion
Ectropion (eyelid folding outward) is a common condition in dogs, usually affecting the lower lid. Breeds associated with ectropion include the Cocker Spaniel, the St. Bernard, the Bloodhound, and the Basset Hound.