Cross-eyed cat - not a Siamese cat - in fact a tabby cat - photo by fazen
A Siamese cat is often crossed-eyed (it is thought) to the point that many Siamese cat owners/keepers consider it normal and accept it. Slightly confusingly the cross-eyed condition is sometimes referred to as a squint. However, squinting can and probably more normally refers to the closing/tightening of the eyelid muscles which partially closes the eye. When severe is can be induced by irritants and is called Blepharospasm.
The classic cross-eyed cat look of the Siamese cat and of course other cats, purebred or not, is an entirely different condition. The medical term is Strabismus. It is a condition in which the eyes are not aligned in relation to each other.
The extraocular muscles lack coordination. This lack of coordination can be due either to the brain or the muscles themselves.
A cross-eyed cat may lack proper binocular vision and depth perception as these two skills/senses are a result of having two eyes that work together. Either a one or both eyes can be misaligned.
In the Siamese cat it has been thought that the breed suffers from an inherited convergent vision (cross-eyed cat - see header picture). This cat health problem may be due to a disrupted visual pathway. A visual pathway is the pathway or route followed by the signals generated by the retina of the eye, which travels from the eye to the primary visual cortex, or V1 of the brain. This route goes via a "relay station" the LGN (lateral geniculate nucleus).
Sometimes Siamese kittens have a mild "squint" or are cross-eyed, which is naturally corrected later on. The condition is inherited and it could be monogenic or polygenic. More research is required. See Siamese cat health problems for more on the most popular purebred pedigree cat.
Cross-eyed cat to Traditional Siamese cat
Source:
- http://www.hhmi.org
- Wikipedia
- Robinson's Genetics for Cat Breeders & Veterinarians
Actually the cat in the photo posted above may be a lynx (lynx=tabby) pointed (pointed=face, ears,feet & tail) Siamese/Siamese mix. We have two lynx point Siamese cats. One a purebred Siamese specifically bred to have "lynx" points the other is a rescue whose mother was Siamese and father is assumed to be a tabby. One of ours is also cross-eyed and perfectly healthy.
ReplyDeleteThe cat in the picture looks Balinese to me and may be a Balinese mix as I believe my cat is. Many Balinese have striped points like a tabby and as they get older these stripes sometimes become more prominent even to the point of the the back and legs becoming striped.
ReplyDeleteIn the 1950's, a few Siamese breeders, who noticed they sometimes had kittens with longer hair than the ideal, decided to get together and develop a longhaired Siamese breed.
The Balinese head forms a long, tapering wedge with a straight profile, the same as it's Siamese ancestry. The ears are large and continue the wedge. The eyes are deep, vivid blue and almond-shaped, set at a slant. Balinese have a dramatic look: alert, curious and regal.