Beagles are relatively hardy dogs, but they are prone to certain health problems, some of which involve their eyes. Besides glaucoma and Progressive Retinal Atrophy, present in many species of dogs, Beagles also suffer from cherry eye and a condition called distichiasis. Fortunately, neither of these conditions is as serious as Retinal Atrophy and in the overwhelming majority of cases both can be corrected by surgery and neither lead to permanent blindness.

The condition known as cherry eye, or medically as canine nictitans gland prolapse, involves the third eyelid. This is a transparent structure right over the eye that in some species can be horizontally drawn over the eye for the purpose of protecting it in various situations; polar bears use it against snow blindness, beavers use it when diving under water. The third eyelid contains a gland, the nictitans gland, which in some breeds can protrude; when it does, it becomes very red and highly visible. Experts are not exactly sure what causes the gland to protrude, though some think that the connective tissue that holds the gland in place may become weak due to hereditary factors. The protrusion of the gland leads to a chronic inflammation of the eye and eye discharge; dry eye can also occur, given the fact that the gland contributes to the production of tears. The gland may also swell in size due to improper circulation of blood.

Nowadays, cherry eye is treated with the surgical replacement of the gland; traditionally, the gland was simply removed, but this leads to a chronic case of dry eye that has to be treated with the regular administration of eye drops. Since the gland is important in keeping the eye moist, veterinarians consider replacement the solution to the problem. A veterinarian will either use the traditional tucking method to get the gland back in place or the newer method of removing a piece of tissue from over the gland and using tiny stitches to pull the two edges together, forcing the gland to return to its location.

Another eye problem from which Beagles suffer is distichiasis, in which one or more eyelashes grow into the eyelid, causing serious irritation; the eyelashes are not found in their normal location and often grow out of glands at the margin of the eyelid. Either the lower or upper eyelid may be involved. Though not a serious condition, the abnormal eyelashes can lead to inflammation, copious tearing and squinting and could cause ulcers and scars on the cornea. In some cases, the dog shows no sign of being disturbed by the abnormal eyelashes, so no treatment in necessary; veterinarians often prescribe an ophthalmic lubricant in mild cases. If the dog shows signs of being seriously affected, like presenting scars or ulcers, then surgery is undertaken. Depending on the number and location of abnormal eyelashes, either a portion of the eyelid is removed or the glands from which the eyelashes are growing are either cauterized or frozen with cryotherapy.