host posted on May 20, 2011 13:00
A cataract is an abnormal opacity (cloudiness) of the lens or its outer covering (capsule). The opacity may range from a tiny spot to total loss of transparency. The lens is an M&M-shaped transparent structure that lies directly behind the iris and pupil. The cornea, lens and fluids within the eye are elements that bend (refract) light waves to form an image upon the retina. The cornea accounts for about 80% and the lens for about 20% of the light-bending action.
Causes of cataracts include heredity, metabolic defects, diseases like diabetes, injuries and aging. The rate of cataract development ranges from a few days to years.
Lens removal (cataract surgery) in animals is not as ssimple as in people due to structural and physiologic differences between people and animals. Animals require more post-op pain medication and the recovery time is much longer than with people. Some animals do not see for several weeks after surgery.
Some pets may not be suitable for cataract surgery due to age, health and psychological make-up. If your pet is unable to undergo surgery, do not be discouraged, since most dogs tolerate loss of sight with very few problems.
Image courtesy of Hill's Pet Nutrition®.