Oct. 29, 2004 -- -- Now dogs may face the backyard taunt of being called "four-eyes." Or you may see a blind dog walking down the street wearing stereotypical dark glasses. No, I'm not kidding.
Doggles, a manufacturer of protective eyewear for dogs, is trying out a line of canine corrective lenses for dogs that can't see far beyond the end of their noses.
First of all, dogs don't see as well as you might think. A dog's visual acuity is considerably less than that of a normal human according to Dr. Stanley Coren, author of "How Dogs Think: Understanding the Canine Mind."
The overall effect for normal dogs is something like viewing the world through a fine mesh gauze or a piece of cellophane that has been smeared with a light coat of petroleum jelly.
"If dogs drove cars, they'd have about 20/50 vision and their driver's license would say corrective vision required," Coren said.
Well, dogs don't drive cars, but they do need to see cars coming down the road. Or squirrels running around the back yard, a set of stairs or Mom holding a treat in her hand.
For mature mutts that begin to lose their eyesight or for dogs that have lost their vision due to cataracts or unsuccessful cataract surgery, doggie glasses may be just what the doctor ordered.
Historically, there has been nothing to help dogs that were becoming blind as bats. We just let them get by as best as they could with their other senses. But now veterinary-approved canine corrective lenses can give many dogs the gift of sight again.
Dr. Michael Brinkman, a veterinary ophthalmologist in Las Vegas, said the Doggles company has worked with him to produce the corrective eyewear for dogs, which he is currently testing on some of his patients.
In particular, he said, the lenses can be used to correct the farsightedness that occurs in dogs that have had cataract surgery but could not have lens implants. A dog that has undergone cataract surgery without receiving a lens implant will be able to spot a cat across the street but perhaps not see a piece of kibble in front of its food dish. Typically, dogs without lenses are about twice as farsighted as humans without lenses.
Brinkman notes that these dogs -- from Great Dane to tiny Chihuahua -- all have a fairly similar refractive prescription so you wouldn't need hundreds of types of glasses to fit dogs. Specially trained veterinarians are able to determine a dog's prescription by performing a retinoscopy, similar to how a human ophthalmologist determines the prescription for a very small child who is too young to read the eye chart.
Roni DiLullo, president of the Doggles company, says the glasses are made to order with any prescription obtained from a veterinary ophthalmologist. The prescription dog glasses cost less than $100.
To determine if the prescription lenses really help the dog see better requires a combination of subjective observation by the owner along with asking the dog to identify familiar things like a favorite toy.
Doggles, which even makes prescription sunglasses for dogs, is also offering solid black lenses for dogs that are blind.
The opaque lenses aren't for vanity or cosmetics, but they serve a number of important services.
The black lenses comfort dogs with failing eyesight who are super-sensitive to light and they protect eyes from damage when blind dogs bump into things. The lenses also serve as a protective patch after eye surgery and they help to alert people who may interact with the dog that it is unable to see.
Doggles also makes dog goggles, which are typically used to protect the eyes of dogs who ride in cars and trucks and are in danger of having their eyes damaged by flying debris, or for certain breeds of dogs, like German shepherds who have a dry eye condition called Keratoconjunctivitis Sicca or a condition called Chronic Superficial Keratitis, or Pannus, where the eye becomes covered with a brown covering. With KCS and Pannus, environment can be a contributing factor. Pannus is caused by exposure to ultraviolet light, and a reduction in the exposure to UV rays is recommended for the long-term care and treatment of the condition.
Doggles are also used to protect military dogs in the Middle East from blowing sand, shield the eyes of search and rescue dogs like the ones who worked at Ground Zero after 9/11, and protect police dogs from environmental hazards. Many dogs wear Doggles while riding in cars, trucks or on motorcycles, whereas others, like my wife Teresa's little papillon/poodle/Yorkie cross, Quixote, wear them for fashion and fun.
If you require more information about healthy eyes, eye disease, treatments and correction in pets, visit the Web site of the American College of Veterinary Ophthalmology at www.acvo.org.
Dr. Marty Becker is a veterinarian, author, educator and a regular guest on ABC News' Good Morning America