Shih Tzus are one of the most eye-problem-prone breeds in existence. A study examining 1,000 Shih Tzu eyes found that 96.4% had at least one ophthalmic abnormality, and only 3.6% were completely normal. This isn’t bad luck or poor care. It’s a direct consequence of the breed’s flat face and prominent eyes, which create a perfect setup for a wide range of ocular conditions.
Why Their Face Shape Causes Problems
Shih Tzus are brachycephalic, meaning they have a shortened skull and a flat facial structure. This gives them shallow eye sockets, which causes the eyes to sit more forward and exposed than in longer-snouted breeds. The eyelid openings are often too large for the size of the eye, and many Shih Tzus can’t fully close their lids, leaving a portion of the eye’s surface constantly exposed to air, dust, and debris.
These features reduce the eye’s natural protection while simultaneously increasing irritation. Flat-faced anatomy also interferes with normal tear drainage. In most dogs, tears flow from the eye through small ducts into the nasal cavity. In Shih Tzus, the compressed facial structure can physically obstruct these drainage pathways, causing tears to overflow down the face instead of draining internally. That’s why tear staining is so common in the breed.
The Three Most Common Conditions
Nearly half of all Shih Tzu eye abnormalities come down to just three conditions. Caruncular trichiasis, where the small fleshy bump at the inner corner of the eye grows hair that rubs against the eye’s surface, affects about 21% of eyes and is bilateral (present in both eyes) in roughly 20% of dogs. Reduced tear film stability, where the protective tear layer breaks down too quickly, affects about 17.6% of eyes. And medial canthal entropion, where the inner eyelid rolls inward against the eye, affects about 10.4%.
These three conditions alone account for problems in 49.1% of Shih Tzu eyes. They tend to cause chronic, low-grade irritation rather than sudden emergencies, which means they can go unnoticed for a long time while quietly damaging the cornea.
Dry Eye and Tear Film Problems
Keratoconjunctivitis sicca, commonly called dry eye, is one of the most prevalent disorders in the breed. It happens when the eyes don’t produce enough tears or when the tear film evaporates too quickly. Without adequate moisture, the cornea becomes inflamed, painful, and vulnerable to infection and scarring.
Veterinarians diagnose dry eye using a simple paper strip placed against the lower eyelid to measure tear production over one minute. Normal Shih Tzu readings fall around 16 to 19 millimeters per minute, depending on whether the eyes are open or closed during the test. Values below 15 indicate a problem. Dry eye in Shih Tzus often requires lifelong management with tear-stimulating drops or artificial tear supplements.
Corneal Ulcers
The cornea is the clear outer layer of the eye, and it’s packed with nerve endings. When it gets scratched or damaged, the result is intense pain, excessive blinking, squinting, and watery discharge. Shih Tzus are especially vulnerable because their prominent eyes are more exposed to scratches from plants, other animals, or even their own facial hair.
Beyond trauma, corneal ulcers in this breed frequently develop as a secondary problem. Dry eye removes the protective tear layer. Abnormal eyelashes rub against the surface. Eyelids that don’t close fully leave areas of cornea exposed overnight. Any of these can erode the corneal surface over time. If you notice your Shih Tzu suddenly holding one eye shut, pawing at their face, or developing a cloudy spot on the eye, that warrants prompt veterinary attention, as untreated ulcers can deepen rapidly.
Eyelash Abnormalities
Shih Tzus are predisposed to two types of abnormal eyelash growth. Distichia are extra lashes that grow from the eyelid margin and rub against the cornea. Ectopic cilia are hairs that grow through the pink tissue lining the inside of the eyelid, poking directly into the eye’s surface. Both conditions share a similar origin, but ectopic cilia tend to cause more severe pain and are more likely to produce corneal ulcers.
Mild cases of distichia sometimes cause no symptoms at all and can be monitored. When either condition causes visible discomfort or corneal damage, surgical removal of the offending hairs is the standard treatment.
Proptosis: When the Eye Displaces Forward
Because Shih Tzus have shallow eye sockets, relatively minor trauma (a fall, a scuffle with another dog, or even being grabbed too firmly by the scruff) can cause the eyeball to pop forward out of the socket. This is called proptosis. The eyelids get trapped behind the widest part of the eyeball, and swelling prevents the eye from sliding back into place on its own.
Proptosis is an emergency. The longer the eye stays displaced, the greater the risk of permanent damage to the optic nerve and surrounding muscles. If this happens, keep the eye moist (a damp, clean cloth laid gently over it) and get to a veterinarian immediately.
Progressive Retinal Atrophy
Progressive retinal atrophy (PRA) is a genetic condition where the light-sensing cells at the back of the eye gradually deteriorate, eventually leading to blindness. In Shih Tzus, it’s typically a late-onset form, with clinical signs appearing around age 7 to 8 on average. Early signs include difficulty seeing in dim light, reluctance to navigate stairs or unfamiliar rooms, and eyes that appear more reflective than usual.
There is no treatment that stops or reverses PRA. The progression varies, but it ultimately leads to complete vision loss. Dogs generally adapt well to blindness in a familiar environment, especially when the change is gradual. Genetic testing before breeding can help reduce the prevalence of this condition in the breed.
Cataracts
Cataracts, where the lens inside the eye becomes cloudy and blocks light, are another condition listed among the most prevalent Shih Tzu eye disorders. They can develop due to genetics, aging, diabetes, or as a complication of other eye diseases. You’ll notice a whitish or bluish haze in the pupil that progressively worsens.
Surgical removal (phacoemulsification, essentially the same technique used in human cataract surgery) has an overall success rate of about 79% in dogs. However, small breeds over age 8 have a significantly higher failure rate than younger dogs of the same size. This means earlier detection and intervention tend to produce better outcomes. Not every cataract requires surgery. Small, slow-growing cataracts that don’t significantly affect vision can sometimes be monitored, though they do tend to progress over time.
Pigmentary Keratitis
Pigmentary keratitis is the gradual buildup of dark pigment across the cornea. It’s the eye’s defensive response to chronic irritation, whether from dry eye, abnormal lashes, entropion, or the constant low-level exposure that comes with prominent eyes and incomplete eyelid closure. Over time, the pigment can spread enough to obstruct vision.
This condition is particularly common in Shih Tzus precisely because so many of the underlying irritants are built into the breed’s anatomy. Treating the root cause of irritation (managing dry eye, correcting eyelid problems, removing abnormal lashes) can slow or sometimes partially reverse the pigmentation.
Daily Eye Care for Shih Tzus
Given how common eye problems are in this breed, daily maintenance isn’t optional. Gently wipe the face, eye corners, and chin each day using a soft damp cloth or pet-safe wipes, then dry the area thoroughly. Moisture left sitting in the facial folds promotes bacterial growth and worsens tear staining.
Keep the hair around the eyes trimmed short or secured in a topknot. Facial hair that drapes across the eyes acts like a constant irritant, and it can also physically block tear drainage ducts. Use only dog-safe, tearless products near the face. Avoid anything containing hydrogen peroxide, which can cause severe damage if it contacts the eye. Some over-the-counter tear stain removers lack evidence of effectiveness and may be harmful.
There is some evidence that daily probiotics can reduce tear staining, though improvement typically takes a couple of months to become visible.
Screening and Early Detection
The American College of Veterinary Ophthalmologists recommends annual eye exams for dogs in breeding lines of all breeds, with certifications expiring after one year to encourage repeat screening. For Shih Tzu owners who aren’t breeding, a baseline eye exam with a veterinary ophthalmologist is still worth considering, especially given the 96.4% abnormality rate in the breed. Many of the most common conditions are bilateral and slowly progressive, making them easy to miss at home until significant damage has occurred.
Watch for squinting, redness, cloudiness, excessive tearing, pawing at the face, or any change in eye appearance. In a breed this predisposed to eye disease, catching problems early is often the difference between simple management and permanent vision loss.