Big bulging eyes look cute — but they're also exposed and unprotected. Among flat-faced dogs seen by eye specialists, about 4 in 10 had corneal ulcers. Daily eye checks help you catch problems early. And if your Frenchie's eye ever pops out of socket — RUN to the ER.
Eye out of socket (proptosis) — stop him from pawing at it (hold his paws gently or put a cone on him), keep it moist with sterile saline without pressing, do NOT push it back, and go to the ER now. Visible corneal ulcer or hole (descemetocele, perforation). Sudden cloudiness with severe pain (squinting, won't open eye). Profuse green/yellow discharge with redness appearing suddenly. Blood in or behind the eye (hyphema). Severe trauma (hit by car, dog fight, fall) — even if eye looks OK.
I. What BOS Is
BOS = Brachycephalic Ocular Syndrome. Not one disease — a syndrome where shallow eye sockets, exposed corneas, large eyelid openings, incomplete blinking, and abnormal eyelashes all combine to chronically damage the ocular surface.
Sebbag et al. 2023 (Veterinary Ophthalmology) called it a "pandemic of ocular surface disease," driven by demand for flat-faced breeds.
II. The 9 Components of BOS
- Shallow eye sockets (exophthalmia) — globe sits more exposed/forward, little bony protection
- Macroblepharon — excessively wide eyelid opening
- Lagophthalmos — incomplete blinking, especially during sleep
- Pigmentary keratitis — brownish-black melanin on cornea from chronic irritation
- Medial canthal entropion — inner corner eyelid rolls inward; nasal hairs/folds rub cornea
- Trichiasis / distichiasis — abnormal eyelashes scrape cornea
- Exposure keratitis / corneal ulceration
- Tear film instability (qualitative dry eye — see KCS)
- Proptosis risk — globe can pop out of socket from minor trauma
III. How Common — Costa et al. 2021
93 flat-faced dogs seen at two university eye clinics (38 of them Frenchies):
| Condition | Frequency |
|---|---|
| Macroblepharon | 47% |
| Corneal ulcers | 44% (and 11.18× odds vs crossbreeds) |
| Corneal pigmentation | 36% |
| Corneal fibrosis (scarring) | 25% |
| Entropion | 22% |
| Trichiasis | 16% |
| Distichiasis | 16% |
| KCS | 12% |
IV. Eye Injuries from Minor Trauma
Frenchie eyes protrude and don't have full blink protection. Everyday events cause damage:
- Swat from another dog or cat → corneal scratch
- Running through bush, branch, tall grass → ulcer
- Bedding fibers, hay, mulch → corneal abrasion
- Self-trauma when scratching face → ulcer
- Wind exposure on car rides → cornea dries enough to irritate
V. Daily Prevention — The Highest Leverage Habit
- Lubricating eye drops made for dogs, every day for life — ask your vet which ones. Never use human eye drops.
- Wipe inner corner with sterile saline pads daily — debris, mucus, irritants from skin folds
- Examine eyes daily under good light — cloudy spots, redness, squinting, brown pigment
- Ask your vet whether your dog needs a hydrating eye gel at bedtime, and which one — it helps eyes that do not close fully during sleep
- Avoid grass/branches at face height on walks
- No rough play with eye-level hazards
- A yearly eye check with a tear test (Today’s Veterinary Practice)
Daily hygiene and lubrication help protect the eye surface — which lubricant and how often, your vet decides. But most owners only start AFTER damage. "Wait and see" with Frenchie eyes costs vision and money.
VI. Surgery Options
- Medial canthoplasty — partial closure of inner eyelid corner. One surgery that fixes several BOS problems at once. Reduces eye aperture, corrects medial entropion, improves tear distribution, removes nasal hairs from corneal contact.
- Standard entropion repair (Hotz-Celsus) — for lateral entropion only
- Tarsorrhaphy — temporary partial eyelid suturing for proptosis recovery
- Conjunctival grafts — for deep ulcers
- Corneal grafting — for perforations or severe pigmentary keratitis
VII. Pigmentary Keratitis Treatment
- Topical cyclosporine (Optimmune) — primary, slows progression; your vet or eye specialist decides
- Topical tacrolimus — more potent alternative; your vet or eye specialist decides
- Topical corticosteroids — only when no ulcer present (steroids worsen ulcers), and only on your vet’s prescription
- Pigment usually does NOT regress fully — goal = STOP further progression
- Surgery (superficial keratectomy) for advanced vision-threatening cases — rarely done because of its risks (VCA)
VIII. Proptosis Specifically
In an older study of 66 dogs of all breeds, about 1 in 4 popped-out eyes kept vision, and flat-faced dogs had a better chance (Gilger et al. 1995). Fast repair gives the best chance to save sight. Frenchies are among the highest-risk along with Pugs and Pekingese (shallow orbits).
References
- Sebbag 2023 — Pandemic of Ocular Surface Disease in Brachycephalic Dogs. Wiley Online Library
- Clinical signs of BOS in 93 dogs. PMC7836154
- VetCompass — Corneal Ulcerative Disease. PMC5471714
- Today's Veterinary Practice — Addressing BOS. TodaysVeterinaryPractice.com
- Clinician's Brief — Top 5 Ocular Complications of Brachycephaly. CliniciansBrief.com
- VCA — Pigmentary Keratitis. VCAhospitals.com
