The eyesight in our dogs changes with age.
Researchers based at the Nestlé Purina Research Center in Missouri have discovered that our dogs become more near-sighted as they age. Their results were published in the journal PLoS One.
This investigation used an instrument called an autorefractor to measure the dogs’ eyesight in indirect and direct lighting conditions. The study involved nine Beagles ranging in age from 1 to 14 years. Before entering the study, the dogs were examined to confirm that none of them had cataracts.
Measurements were taken on three different days of the week for a period of six weeks.
The researchers found a remarkable difference between the younger and older dogs. The older dogs had a much-reduced ability to see at longer distances (far-sightedness) compared to the younger dogs. Younger dogs were also able to make larger accommodation changes from indirect light to direct light conditions, indicating a more flexible lens.
Humans are the opposite in terms of length of sight. As we age it can become more difficult to read and see things at shorter distances whereas our ability to see at distances is often not affected (although some older people do have difficulties adjusting to night and low-light conditions, just as the dogs in this study did).
So if your dog is getting older and you notice that they can’t pick up on your body language and signals, there’s a physical reason for it.
Through my own experience working with older dogs, I recommend using a light that helps your senior dog adjust to low-lighting conditions. See my post on the PupLight, for example.
Kathleen Crisley, specialist in dog massage, rehabilitation and nutrition/food therapy, The Balanced Dog, Christchurch, New Zealand