An age-related cataract is a clouding of the eye’s natural lens, a small, transparent disc located behind the colored part of your eye, the iris. In a healthy eye, this lens is clear, allowing light to pass through and focus on the retina. As people age, the proteins that make up the lens can begin to break down and clump together, creating cloudy patches. This process is similar to looking through a foggy or frosted window, causing vision to become blurry and dim. It is a common condition and a natural part of aging.
Symptoms of Cataracts
The onset of cataracts is gradual, with symptoms slowly progressing over time. One of the most common initial signs is a general blurring or dimming of vision that cannot be corrected with glasses. You might feel as if your eyeglass lenses are constantly dirty, even when they are clean. Night vision often becomes increasingly difficult, and you may notice halos or streaks appearing around lights, especially when driving after dark. This can be accompanied by a heightened sensitivity to bright sunlight and glare.
As the cataract develops, your perception of color may change, with colors appearing faded or having a yellowish tint. Some individuals experience double vision in a single eye. Another indicator is the need for frequent changes to your eyeglass or contact lens prescription as your vision fluctuates. In some cases, near vision might temporarily improve, a phenomenon sometimes called “second sight,” but this effect is not permanent.
Causes and Associated Risk Factors
The fundamental cause of an age-related cataract is the structural change in the proteins within the eye’s lens. Over decades, these proteins, known as crystallins, can degrade and aggregate into clumps, which scatters light and prevents it from focusing clearly on the retina. This breakdown is a natural part of the aging process, as the lens becomes less flexible and transparent. Oxidative stress, an imbalance between cell-damaging free radicals and the antioxidants that neutralize them, also contributes to this protein damage.
While aging is the primary driver, several risk factors can accelerate cataract formation.
- Prolonged and unprotected exposure to ultraviolet (UV) radiation from sunlight.
- Certain medical conditions, most notably diabetes.
- Lifestyle choices like smoking and excessive alcohol consumption.
- A family history of the condition.
- Previous eye surgery or injury.
- The long-term use of corticosteroid medications.
Cataract Treatment Options
When symptoms begin to interfere with daily activities, surgery is the only effective treatment to restore clear vision. Non-surgical approaches, such as updating eyeglass prescriptions, using anti-glare coatings on lenses, and increasing lighting for reading, can provide temporary relief in the early stages. These measures, however, do not stop the cataract from progressing.
Cataract surgery is a common and safe outpatient procedure, often taking less than 20 minutes to perform. During the operation, the surgeon removes the clouded natural lens. The most common technique is phacoemulsification, where the lens is broken up using sound waves and then gently suctioned out through a tiny incision.
Once the natural lens is removed, it is replaced with a clear, artificial lens called an intraocular lens (IOL). This IOL is a permanent implant made of a plastic-like material that fits into the same lens capsule that held the natural lens. Monofocal IOLs are the standard and are set to provide clear vision at a single distance—usually far away—meaning reading glasses are still needed for near tasks. Premium IOLs, such as multifocal or astigmatism-correcting (toric) lenses, can reduce dependence on glasses by providing clear vision at multiple distances or correcting pre-existing corneal irregularities.
Prevention and Eye Health
While cataracts cannot be entirely prevented, certain lifestyle choices may help slow their development.
- Protecting your eyes from the sun’s UV rays by wearing sunglasses that block 100% of UVA and UVB rays and a wide-brimmed hat.
- Quitting smoking, as it is a known risk factor.
- Managing other health conditions, particularly controlling blood sugar levels for those with diabetes.
- Eating a diet rich in antioxidants, found in colorful fruits and vegetables.
- Attending regular comprehensive eye examinations, especially for those over 40, for early detection and monitoring.