What is a cataract? What types of cataracts are exist? A cataract is a thick, cloudy area that forms in the lens of the eye. A cataract begins when proteins in the eye type clumps that avoid the lens from sending out clear images to the retina. The retina works by converting the light that comes through the lens into signals. It sends out the signals to the optic nerve, which brings them to the brain.
It develops gradually and ultimately hinders your vision. You may wind up with cataracts in both eyes, but they generally do not form at the very same time. Cataracts are common in older people. Over half of people in the United States have cataracts or have gone through cataract surgery by the time they’re 80 years old, according to the National Eye Institute.
Are There Different Types of Cataracts?
There are 3 main types of age-related cataracts: nuclear sclerotic, cortical, and posterior subcapsular. As an individual ages, any one type, or a combination of any of these 3 types, can establish gradually.
Nuclear Sclerotic Cataracts
This is the most common kind of age-related cataract, caused mostly by the hardening and yellowing of the lens in time. “Nuclear” describes the progressive clouding of the central part of the lens, called the nucleus; “sclerotic” describes the hardening, or sclerosis, of the lens nucleus.
As this type of cataract advances, it alters the eye’s ability to focus, and close-up vision (for reading or other types of close work) may briefly improve. This symptom is described as “2nd sight,” but the vision enhancement it produces is not permanent.
A nuclear sclerotic cataract progresses slowly and may require several years of gradual advancement before it starts to impact vision.
“Cortical” refers to white opacities, or cloudy areas, that develop in the lens cortex, which is the peripheral (outdoors) edge of the lens. Modifications in the water material of the lens fibers create clefts, or fissures, that look like the spokes of a wheel pointing from the outdoors edge of the lens in towards the center.
These cracks can cause the light that enters the eye to spread, developing issues with blurred vision, glare, contrast, and depth understanding. People with diabetes are at risk for establishing cortical cataracts.
Posterior Subcapsular Cataracts
This kind of cataract starts as a little nontransparent or cloudy area on the “posterior,” or back surface of the lens. It is called “subcapsular” due to the fact that it forms beneath the lens capsule, which is a little “sac,” or membrane, that encloses the lens and holds it in place.
Subcapsular cataracts can interfere with reading and create “halo” results and glare around lights. People who use steroids, or have diabetes, extreme nearsightedness, and/or retinitis pigmentosa may develop this type of cataract. Subcapsular cataracts can establish quickly and symptoms can become noticeable within months.
Please note: A cataract is not a tumor, nor is it a “movie” or tissue growth that establishes over the cornea, or front surface of the eye. Although most of cataracts are not visible to the naked eye, there are some instances where the pupil can appear white due to the fact that the lens is entirely clouded by an extremely thick cataract.