With aging comes a loss of elasticity in the lens of the eye causing an inability to focus on nearby objects. The pupil is unable to expand and contract to the same degree as in youth, with the result that old dogs do not see as well in the dark and have a similar problem with very bright light. Ultraviolet light is damaging to lenses and, over time, may result in cloudiness. Additionally, chemical/genetic disease may also result in cataracts. Older dogs tend to have "hazy-looking" eyes, a condition known as, lenticular or nuclear sclerosis that does not seem to effect vision.

With age, drainage of the eye's aqueous humor may become reduced resulting in increased internal pressures and eventually glaucoma and blindness. Old age degeneration of the retina may result in Central Progressive Retinal Atrophy if it affects only the central vision. This is the area of the dog's vision that is the sharpest and generally the most important.

If overall degeneration of the retina occurs, it is known as Progressive Retinal Atrophy. Corneal disease may occur with calcium deposits forming in the cornea. This condition often results in extreme photophobia (fear of light), and has been associated with dementia and blindness in the dog.

Next Page - Ears