How Cataracts Affect Vision
Your vision changes throughout your life. Many changes are due to the natural aging of eye tissue, decreasing the sharpness of your vision. You may need reading glasses or turn on more lights to see clearly.
Cataracts are a common, often age-related eye problem. Many people develop cataracts by the time they reach 80, but the condition can affect children.
Cataracts are a leading cause of blindness in the US. Unfortunately, a cataract is irreversible, but there are treatment options to help restore your vision.
Cataracts & the Lens
A cataract forms in the eye’s crystalline lens. The lens is a clear, curved tissue behind the iris (the colored part of the eye). A healthy lens is flexible and soft, changing shape to focus light on the retina (the light-detecting tissue at the back of the eye).
The lens is made of proteins. These proteins can break down and clump together when the tissue ages or is damaged. While healthy eye tissue is transparent, clumped proteins can block light. The clumps also limit the lens’ flexibility, preventing it from changing shape to focus light. As a result, the cloudy spot (a cataract) impairs vision.
Usually, a cataract grows slowly over time. In the early stages, you may notice only slight changes to your visual sharpness. Unfortunately, as the clump grows, the lens becomes rigid, and light is blocked.
Cataract symptoms can vary depending on the stage and location. However, typical symptoms include:
- Blurry or foggy vision (all distances)
- Colors appearing faded or yellow
- Difficulty seeing in dim light or at night
- Glare or halos appearing around lights
- Light sensitivity
- Seeing double
Early-stage cataracts cause reduced vision, but later-stage cataracts can cause legal blindness or even complete blindness.
Cataracts develop for many reasons, but they can be categorized based on where or how they form:
- Nuclear cataracts form in the center of the lens (the nucleus). You may initially experience increased nearsightedness (poor distance vision) or temporarily improved close vision. But, vision will decrease at all distances as the nuclear cataract develops. Additionally, the lens gradually turns yellow or brown, making colors appear yellowish.
- Cortical cataracts affect the edges of the lens, appearing wedge-like or white streaks. Over time, cortical cataracts grow, moving closer to the lens center. As a result, you may notice poor depth perception, light sensitivity, and decreased vision in low light.
- Posterior subcapsular cataracts form at the back of the lens and can develop quickly. The cataract begins as a tiny, opaque area, initially interfering with close vision. Then, as it grows, it can reduce vision in low lighting and cause glare.
- Congenital cataracts develop in children, either before birth or in childhood. The condition may be inherited, or it may be caused by an eye injury or a complication of infection. Congenital cataracts may not affect vision but are usually removed soon after detection.
What Causes Cataracts?
The most significant risk factor for developing a cataract is aging, as the proteins in the lens begin breaking down around age 40. However, other risk factors can cause cataracts to develop earlier or progress more quickly.
Some risk factors known to contribute to cataract development include:
- Diabetes—higher blood sugar levels can cause blood vessels to leak inside the eye, causing lens tissue to swell.
- Drugs & medications—various medications can have eye complications, including corticosteroids, chlorpromazine, and other phenothiazine-related medications.
- Excessive alcohol consumption—multiple studies have linked cataract formation in patients with higher alcohol consumption.
- Family history—people have a higher chance of developing a cataract when a close relative has cataracts.
- Nutritional deficiency—eye health is supported by diet and nutrition, and some studies suggest antioxidants can help decrease cataract development.
- Smoking—people who smoke are 3 times more likely to develop cataracts.
- Sun overexposure—unprotected exposure to ultraviolet (UV) radiation can lead to cataract formation.
Cataracts vs. Presbyopia
In the early stages of cataract development, patients may experience only a few vision problems or none at all. However, you may also mistake blurry close vision for another common vision problem—presbyopia. Both problems occur because the lens becomes less flexible, but presbyopia only affects close vision.
Neither presbyopia nor cataracts are reversible, but both can be treated or improved.
Managing & Treating Cataracts
Early or mild symptoms caused by cataracts are usually easily managed with nonsurgical methods. For example, you may benefit from an anti-glare coating on prescription lenses or adding lighting to dim spaces. Patients with cataracts may need their prescription updated frequently, but glasses and contacts can help sharpen vision at all distances.
Late-stage symptoms can severely impair vision or cause total blindness. When cataracts progress, your eye doctor can determine if you’re a candidate for cataract surgery. Your clouded natural lens is removed and replaced with an artificial lens.
Talk About Your Options
When you notice vision changes, it’s time for a checkup. We want to help you preserve your vision. Regular eye exams are crucial for detecting changes to eye tissue. Our eye doctors assess your eyes to determine if vision changes are caused by natural aging, eye disease, or another problem. After getting to know you and your vision, we can work together to find solutions tailored to your needs. Book an appointment with Lake Eye Associates to talk about your options.