Does Your Pet Need Glasses?
June 15, 2018
Do you know how well your dog can see? Surprisingly, your dog may not see as well as you might think. While perfect vision for a human is 20/20, a dog's average visual acuity is around 20/75. Veterinary ophthalmologists suggest a dog's vision is a little greasy, sort of like a human looking through a fine piece of gauze or oil-smeared sheet of clear plastic. Although many people mistakenly think dogs are colorblind, they are not. Where a human's central retina contains 100% cones, a dog's contains about 20% cones, which means humans are five times more receptive to colors. Moreover, human color vision is trichromatic (red, green and blue), whereas a dog's is dichromatic, or two colors.
Common Vision Impairments in Canines
Vision loss and blindness in dogs has many causes that range from genetics, aging, injury and disease. Blindness can also be a symptomatic response to a more serious medical condition or systemic illness. Indeed, eye infections and eye injuries should never go untreated, including:
- Diabetes - Heredity factors, nutrition, age and obesity can play a role in canine diabetes. About three out of four dogs diagnosed with diabetes will develop cataracts. Better diet and more exercise may help slow symptoms.
- Cataracts - When the clear lens of the eye turns cloudy, it can result in partial to severe blindness. Most dogs can receive lens implants during cataract surgery to help restore normal vision.
- Glaucoma - This painful condition causes damage to the retina and optic nerves due to fluid pressure increases inside the eye. Early intervention is most helpful and both medical and surgical treatments are available.
- Progressive Retinal Atrophy - PRA is a degenerative disease (with no cure) where the cells in the retina start to deteriorate. It is not a painful condition but causes your pet to have reduced low-light and night vision.
- Trauma Related Vision Loss - Like their human counterparts, dogs get eye injuries. Whether the trauma came from fighting, riding with their head out the window of the car or something else, veterinary treatment is needed.
- Blindness - Dogs can adjust to blindness rather quickly with your help. It helps to talk to your dog when entering or exiting rooms or prior to touching them when sleeping. Avoid changes to the home environment.
Canines who adapt well to a partial or complete loss of vision may still show some personality changes, such as an increase in separation anxiety. Overall, your best friend is going to become more dependent upon your instructions and commands. Consider placing bells on other pets and supervise all outside activities.
Help Your Blind Pet Adjust to Vision Loss
Let's start by saying that your pet's loss of vision or blindness is likely harder on you than it is on your best friend. That said there are three basic categories of vision loss including blindness from birth, sudden blindness, and gradual loss of vision. Dogs that are born blind are unaware of any difference. They will rely heavily on their sense of smell and hearing to interact with the world like any other puppy. When vision loss comes from a gradual onset, canines have time to map out their environment; and owners can make household adjustments to create a safe home base. Sudden loss of vision is the most stressful for the owner and pet. Owners may need to limit access to a couple of rooms until larger areas of the home are mastered. Following a loss of vision, your dog will be more dependent upon your verbal commands and implementation of daily routines that follow the same processes.
Left untreated eye disease and eye injuries can cause your pet's vision to deteriorate rapidly. If you suspect your best friend's vision may be impaired, contact PrimeVET to schedule an appointment with our caring veterinarian.