A blue eyed French Bulldog stands out, and that is exactly why sellers promote them. But in adult Frenchies, blue eyes usually come from a pigment gene, most often merle or extensive white, and those genes can also affect hearing and the eyes themselves. Here is what causes French Bulldog blue eyes, when a puppy's blue eyes are just temporary, and what to check.

Do French Bulldog eyes stay blue?

Usually not. Many puppies' eyes look blue or blue-gray when they first open, because the iris has not yet built up its final pigment. As the pigment develops over the first weeks and months, most French Bulldog puppies' eyes change color to brown. Ask your vet if you are unsure at a checkup.

So a young puppy with blue eyes tells you little. A Frenchie whose eyes are still clearly blue as an adult is different: the blue is then usually genetic, and it is worth knowing which gene is behind it.

What causes blue eyes in an adult French Bulldog

A blue iris has little or no pigment.[3] In dogs, three genetic routes are known:[8]

  • Merle (M locus). Merle dilutes pigment in random patches of the coat and often the eyes. UC Davis lists the French Bulldog among the breeds appropriate for merle testing.[1]
  • Piebald and extensive white. White-spotting genes can also leave the iris without pigment.[8]
  • An ALX4 duplication. A 2018 study of more than 3,000 dogs found a DNA duplication near the ALX4 gene strongly linked to blue eyes, mostly in Siberian Huskies and also in non-merle Australian Shepherds. The authors note that before this, merle and piebald were the only known genetic causes.[8] It has not been described as a cause in French Bulldogs.

A gray or "blue" coat is a separate thing. The blue coat color comes from the recessive dilute gene, which turns black pigment gray-blue.[9] A "grey blue eyed French Bulldog" may carry dilute and merle together, so ask for DNA results for both.

Blue eyed merle and white French Bulldogs

Most adult Frenchies sold as blue eyed are merle. A merle dog has one copy of the gene. When two merles are bred together, some puppies can inherit two copies (double merle), and UC Davis warns that double merles "may have auditory, ophthalmologic, skeletal, and other defects," which is why breeding two merles is discouraged.[1] Our double merle French Bulldog guide explains the risks.

A white blue eyed French Bulldog needs extra care in two ways. First, a mostly white dog from merle parents may itself be a double merle. Second, white coats and blue eyes are both tied to inherited deafness. See white French Bulldog deafness and our guide to the pied French Bulldog.

French Bulldog blue eyes: health risks

Blue eyes do not hurt and do not, by themselves, mean a dog sees badly. The concern is what often travels with them:

  • Deafness. Merck says congenital deafness "is often associated with blue eyes and white pigmentation" and is most common in dogs with piebald or merle genes.[2] In merle dogs studied by Strain and colleagues, deafness was uncommon with one copy of merle and much more common with two.[10] A BAER test checks each ear.
  • Eye defects in double merles. These can be serious and present from birth.[1]
  • Iris colobomas. These are gaps in the iris. Merck notes they are "most common in eyes that have more than one color in the iris."[11] Many cause no problems, but an eye vet should look.
  • Squinting is not a "blue eye" trait. If a blue-eyed Frenchie squints, or has redness or discharge, treat it as an eye problem; see French Bulldog red eyes.

Blue eyes and the breed standard

  • AKC (US): eyes "dark, brown or approaching black in color"; lighter brown eyes are "acceptable, but not desirable", and blue or green eyes, or any trace of blue or green, are a disqualification.[4]
  • FCI: eyes dark; "light eyes" are a severe fault and eyes of two different colors (heterochromia) are disqualifying.[5]
  • Royal Kennel Club (UK): eyes "preferably dark and matching."[6] Merle Frenchies are not registered because merle "carries an increased risk of impaired hearing and sight problems."[12]

None of the standards treats blue eyes as a desirable trait.

When "blue" means an eye problem

If your adult Frenchie had brown eyes and one now looks blue, gray, cloudy or hazy, the iris has not changed color. Something in front of it has: swelling of the cornea, a cataract, or glaucoma. Merck lists swelling and discoloration of the cornea, redness and an enlarged eye among glaucoma signs and says the dog "should be seen by a veterinarian immediately."[7]

Go the same day if the cloudy eye is painful, red, squinting or bulging. A slow, painless haze in an older dog also needs an exam; read signs a French Bulldog is going blind.

Buying a blue eyed French Bulldog puppy

Searches for a blue eyed French Bulldog price or puppies for sale often lead to merle litters marketed by eye color. If you are still considering one, ask the seller for:

  1. M-locus (merle) DNA results for both parents and the puppy.
  2. A BAER hearing test result for each ear.
  3. An eye exam by a veterinary ophthalmologist.
  4. The parents' other health tests; see our breeder health tests guide.

Avoid any litter from two merle parents.

Sources and references

  1. UC Davis Veterinary Genetics Laboratory. Merle [Internet]. UC Davis Veterinary Genetics Laboratory; [date unknown] [cited 2026 Nov 3].
  2. Scheifele PM. Deafness in Animals [Internet]. Merck Veterinary Manual; 2025 Aug [updated 2026 Apr; cited 2026 Nov 3].
  3. Louisiana State University School of Veterinary Medicine. Genetics of Deafness in Dogs [Internet]. Deafness in Dogs & Cats; [date unknown] [cited 2026 Nov 3].
  4. American Kennel Club. Official Standard of the French Bulldog [Internet]. AKC; 2018 Apr 10 [cited 2026 Nov 3].
  5. Fédération Cynologique Internationale. FCI-Standard N° 101 BOULEDOGUE FRANÇAIS (French Bulldog) [Internet]. FCI; 2023 Aug 10 [cited 2026 Nov 3].
  6. The Royal Kennel Club. French Bulldog [Internet]. The Royal Kennel Club, Breed Standards; [date unknown] [updated 2025 Aug 1; cited 2026 Nov 3].
  7. Gelatt KN. Glaucoma in Dogs [Internet]. Merck Veterinary Manual; 2018 Jun [updated 2024 Sep; cited 2026 Nov 3].
  8. Deane-Coe PE, Chu ET, Slavney A, Boyko AR, Sams AJ. Direct-to-consumer DNA testing of 6,000 dogs reveals 98.6-kb duplication associated with blue eyes and heterochromia in Siberian Huskies. PLoS Genetics. 2018;14(10):e1007648. doi:10.1371/journal.pgen.1007648.
  9. UC Davis Veterinary Genetics Laboratory. Dilute (D Locus/Blue) [Internet]. UC Davis Veterinary Genetics Laboratory; [date unknown] [cited 2026 Nov 3].
  10. Strain GM, Clark LA, Wahl JM, Turner AE, Murphy KE. Prevalence of Deafness in Dogs Heterozygous or Homozygous for the Merle Allele. Journal of Veterinary Internal Medicine. 2009;23(2):282-286. doi:10.1111/j.1939-1676.2008.0257.x.
  11. Gelatt KN. Disorders of the Anterior Uvea in Dogs [Internet]. Merck Veterinary Manual (Dog Owners version); 2018 Jun [updated 2024 Sep; cited 2026 Nov 3].
  12. The Royal Kennel Club. French Bulldog [Internet]. The Royal Kennel Club, Breeds A to Z; [date unknown] [cited 2026 Nov 3].