vision with a cataract
Clouding of lens
|HOW WE SEE
Our eyes work just like a camera. When we look at an object, light rays reflect off that object and enter our eyes through the cornea. The lens behind the cornea focuses the rays onto the retina which, in turn, converts the rays into electrical impulses that travel through the optic nerve to the brain. The brain converts the electrical impulses into images.
Seeing depends on this entire chain of events. But seeing clear, focused images depends largely on the lens.
COMMON VISION PROBLEMS
People who are nearsighted can see up close, but have difficulty seeing objects at a distance. Myopia is typically caused by an eye that is too long, which causes light to focus in front of the retina.
Farsighted people can see objects at a distance, but have difficulty seeing up close. Hyperopia is typically caused by an eye that is too short, which causes light to focus behind the retina.
Presbyopia is an age-related condition that blurs near vision. It is caused by a gradual loss of flexibility in the eye's natural lens and surrounding muscles.
Sometimes the surface of the cornea is curved more like a football than a basketball, with both flatter and steeper curves. This common irregularity, called "corneal astigmatism,: causes blurred or distorted vision. This occurs when light rays are not focused at one spot to provide clear vision.
CATARACTS: A NATURAL PART OF AGING
According to a study by Alcon, cataracts are the leading cause of visual loss in adults 55 and over. A cataract is a clouding of the natural lens inside your eye. This lens, located behind the iris, works just like the lens of a camera - focusing light images on the retina, which sends images to the brain. The human lens can become so clouded it prevents light and images from reaching the retina.
A cataract can be the reason sharp objects become blurred, bright colors become dull, or seeing at night is more difficult. It may also be why reading glasses or bifocals are used to help you no longer seem to be effective. Vision with cataracts has been described as seeing life though an old, cloudy film. But a cataract is not a "film" over the eye, and neither diet or lasers will make it go away. Nor can it be prevented. Eye injury, certain diseases, or even some medications can cause clouding, but the majority of cataracts are simply the result of the natural aging process. The best way to treat a cataract is with surgery that removes the old, clouded lens and replacing it with a new, artificial lens to restore your vision and, in many ways, significantly improve your quality of life.