With different habitats, different prey, and different predators, it’s only natural that animals should have evolved to possess varying levels of colour vision. Dogs’ eyes are typically between 9.5mm and 11.6mm in diameter, depending on the breed. Eye size clearly isn’t always relative to the size of the animal! Some smaller eyes belong to the rattlesnake, ferret, squirrel and bullfrog, which are all 8mm in diameter. You might be interested to know that human eyes are typically 24mm in diameter, which happens to be the same size as a dolphin eye! The largest eyes belong to the aptly named colossal squid at 280mm, while the blue whale’s eyes surprisingly come in at 150mm. Snakes and, perhaps unexpectedly, bobcats have slits with a more vertical oval shape. Larger mammals such as cows, horses, deer and moose have horizontal oval shaped eyes. Human eyes are round, as are eyes in bears, foxes, birds and turtles. Animals can also develop dry eye, corneal ulcers and pink eye.Īnimal and human eyes come in different shapes and sizes. There are even veterinary specialists dedicated solely to animal ophthalmology! Cataracts are the most common eye condition they deal with, particularly prevalent in dogs, which are usually age-related, or occur as a cause of canine diabetes. Animals suffer from many of the same eye conditions that humans do, from cataracts and glaucoma, to short-sightedness and scratched corneas.