Blindness in dogs can come on suddenly and without warning, or it can start off slowly and progress over time in older dogs. Any dog of any breed can become blind, but some breeds are at an increased risk for eye issues.

Sudden blindness in dogs

Sudden blindness in dogs is a scary condition for dog owners and the dogs themselves. Sudden blindness can happen to any healthy dog, and while it can be alarming, it is not a painful condition. In most cases, sudden blindness is due to a sudden breakdown of the retina, and the cause is often unknown. The retina located in, the back of the eye, is a thin surface that contains rods and cones, which are light-sensing.

An onset of sudden inflammation of the optic nerve can also lead to sudden blindness. It is normally caused by an injury to the eye or other infections and diseases. The optic nerve is a large nerve that is also located in the back of the eye. It collects the signal of the rods and cones and sends it to the brain.

Unfortunately, sudden blindness due to an issue with the retina is a permanent condition. Inflammation of the optic nerve can sometimes be treated, and the dog may regain its vision.

Slow, progressive blindness in dogs

Any dog can gradually lose their vision in one or both of their eyes due to age. Normally a slow degeneration of the retina, it is often referred to as progressive retinal atrophy or PRA for short. Over time, the cones and rods in the retina breakdown and no longer work. This can happen over several months and years. Most dogs will first show signs of having difficulty seeing at night and may walk and bump into things. Just like sudden blindness, this condition is not painful. It occurs more in purebred dogs than mixed breed dogs as it is inherited. There is no effective treatment for PRA. Other eye issues that can lead to progressive blindness in dogs are cataracts, glaucoma, and of course, injury to the eye.

Blindness in dogs may alarm owners, but most dogs will adapt quickly to the environment with the proper supervision.