Did you know that cataracts are so common among older adults that by age 80, more than half of all Americans will either be living with a cataract or have already undergone cataract surgery?
To honor Cataract Awareness Month this June, and address a serious senior healthcare issue, we've put together a fact sheet that will help you stay on top of your eye health.
What is a cataract?
A cataract is a clouding of the lens, the clear part of the eye behind the iris and the pupil that helps to focus light, or an image, on the retina.
In order for the retina to receive a clear image, the lens must be clear.
In a normal eye, light passes through the transparent lens to the retina, a light-sensitive membrane on the back wall of your eye, where it is translated into nerve signals that are sent to the brain.
In an eye that is clouded by a cataract, however, light is diffused as it passes through the lens. When light is unable to focus properly on the retina these images cannot be accurately transmitted to the nerves, and as a result, your vision will appear blurred.
How does a cataract form?
While some cataracts can be caused by injuries or genetic disorders, most cataracts are just the result of getting older.
As we age, our cells regenerate more slowly which causes tissues change. In the eye, our lenses become thicker, less flexible and less transparent. The lens is mostly made of water and protein that must be arranged in a precise way in order to allow light to pass through clearly.
Aging-related changes to the lens cause some of the protein to break down and clump together, causing cloudiness. As the cataract continues to develop, the clouding becomes denser and involves a greater part of the lens.
Because the lens has three distinct layers, all of which must remain transparent for sharp vision, a cataract can form in one of three ways.
- A nuclear cataract is located in the central layer of the lens called the nucleus. In a nuclear cataract, the nucleus tends to darken, changing from clear to a yellow and sometimes brownish color.
- A cortical cataract affects the cortex layer of the lens that surrounds the nucleus. These types of cataracts form in distinctive wedge or spoke shape, and can be identified from their unique appearance.
- A posterior capsular cataract is found on the back of the capsule, the outermost layer of the lens. You can typically identify a posterior capsular cataract through its rapid growth and development.
How do I know if I have a cataract?
Cloudiness or dim and blurred vision is typically the first sign of a cataract, but it may be so slight that you do not notice it at first. As a cataract grows larger, however, it begins to cloud more of your lens which distorts an increasing amount of the light passing through the lens. This then leads to more noticeable signs and symptoms:
- Colors that seem faded or yellowed
- Sensitivity to light that causes lights, during the day and night, to appear too bright. This kind of sensitivity may also cause a halo to appear around light sources.
- Poor or significantly diminished night vision
- Double vision or multiple images in one eye that may eventually fade. Distortion sometimes fade as a cataract spreads and grows larger.
- Constant need to change or update the prescription of your eyeglasses or contact lenses.
Keep in mind that many of these symptoms can also be warnings for other serious eye problems, so if you have any of these symptoms, contact your senior eye care provider to have your eyes tested.
Image Credit: ORBIS UK