Cataracts cause a gradual clouding of the lens inside your eye, leading to blurred vision, glare sensitivity, and faded colors. Most people notice symptoms slowly over months or years, and the changes can be so subtle at first that you don’t realize your vision has shifted. Cataracts disproportionately affect adults over 60, with both frequency and severity climbing steeply after that age.
Blurred or Hazy Vision
The most common early symptom is a general blurriness, as if you’re looking through a fogged-up window. At first this may only be noticeable in one eye or under certain lighting conditions. Over time the cloudiness spreads across more of the lens, and the blur becomes harder to ignore. Tasks that depend on sharp detail, like reading small print, threading a needle, or recognizing faces at a distance, get progressively more difficult.
Because cataracts develop slowly, many people unconsciously compensate by turning on more lights, holding books farther away, or avoiding night driving. You might assume the change is just normal aging. A reliable clue that something more is happening: your glasses prescription keeps changing, but new lenses don’t seem to fully correct your vision the way they used to.
Glare and Light Sensitivity
Cataracts scatter light as it passes through the clouded lens, which makes bright lights feel uncomfortably intense. Oncoming headlights at night are a classic trigger. You may notice halos, rings of light that seem to glow around streetlights, lamps, or car headlights. Daytime glare from sunlight reflecting off windshields or water can also become bothersome.
One particular type of cataract, called a posterior subcapsular cataract, is especially notorious for glare problems. People with this form often see reasonably well in dim rooms but struggle in bright sunlight. This pattern can be confusing because your vision seems fine indoors, then deteriorates dramatically the moment you step outside.
Faded or Yellowed Colors
As the lens clouds, it filters light differently, and colors gradually lose their vibrancy. Blues may look duller, whites may take on a yellowish or brownish tint, and it can become harder to tell similar shades apart. The shift is so gradual that most people don’t notice it until after cataract surgery, when they’re startled by how vivid and blue-white the world looks through a clear lens again.
This yellowing happens because the proteins in the lens break down over time and clump together, physically changing the color of the lens itself. In advanced cases the lens can turn visibly brown, which acts like wearing tinted sunglasses you can never take off.
The “Second Sight” Effect
Some people experience a surprising and temporary benefit early in cataract development. As the center of the lens hardens and changes shape, it increases the eye’s focusing power at close range. If you’ve relied on reading glasses for years, you may suddenly find you can read without them. This phenomenon is sometimes called “second sight.”
It sounds like good news, but it’s actually a sign the cataract is progressing. The same change that improves near vision typically worsens distance vision, making you more nearsighted overall. And the improvement doesn’t last. As the cataract continues to develop, the brief window of better close-up vision gives way to the same blurriness that affects everything else.
Difficulty Seeing at Night
Night vision tends to deteriorate earlier and more noticeably than daytime vision. The combination of reduced light entering a clouded lens and increased scatter from oncoming headlights makes driving after dark one of the first activities people give up. You might also notice that dimly lit restaurants feel harder to navigate, or that you need a brighter bedside lamp to read comfortably.
Double Vision in One Eye
A less well-known symptom is monocular double vision, where you see a ghost image or shadow of an object even with the other eye closed. This happens when the cataract creates uneven areas of cloudiness across the lens, splitting incoming light into two slightly different paths. It’s distinct from the double vision caused by eye alignment problems, which disappears when you cover one eye. Cataract-related doubling persists with one eye open.
How Symptoms Differ by Cataract Type
Not all cataracts feel the same, because the location of the cloudiness within the lens determines which symptoms hit hardest.
- Nuclear cataracts form in the center of the lens. They tend to cause overall blurriness, color yellowing, and the “second sight” phenomenon. These progress slowly over years.
- Cortical cataracts start as white, wedge-shaped streaks at the outer edge of the lens and work inward. Glare and difficulty with contrast are their hallmarks.
- Posterior subcapsular cataracts develop on the back surface of the lens, right in the path of light. They cause significant glare in bright conditions and can interfere with reading faster than other types. These tend to progress more quickly and are more common in younger adults, people who take corticosteroids long-term, and those with diabetes.
It’s possible to have more than one type at the same time, or to have cataracts in both eyes that progress at different rates. This is why one eye may seem noticeably worse than the other.
How Cataracts Are Diagnosed
An eye doctor can detect cataracts during a standard comprehensive eye exam, often before you notice symptoms yourself. The key tool is a slit lamp, a specialized microscope that shines a bright, narrow beam of light into your eye so the doctor can examine the lens in fine detail. They’ll also check your visual acuity (the familiar letter chart), measure the pressure inside your eye, and examine the structures at the back of your eye to rule out other conditions like glaucoma or macular degeneration that could be contributing to vision changes.
You may also be asked to fill out a questionnaire about how your vision affects daily activities: reading, driving, recognizing faces, watching television. This helps determine whether symptoms have progressed enough to consider surgery, since cataracts are only treated when they meaningfully interfere with your life. There’s no medication or eye drop that reverses them. The only definitive treatment is surgical replacement of the clouded lens with a clear artificial one, a procedure that takes about 15 minutes and has a success rate above 95 percent.
When Symptoms Tend to Appear
Most cataracts are age-related and begin forming in your 40s or 50s, though they rarely cause noticeable symptoms that early. The majority of people start experiencing visual difficulties in their 60s or later. Globally, roughly 8 out of every 100 adults over 60 have cataracts significant enough to be counted in disease burden estimates, and prevalence climbs with each decade of life, peaking in those over 95.
Certain factors can accelerate the timeline. Diabetes, prolonged use of corticosteroid medications, previous eye injuries, excessive sun exposure, and smoking all increase your risk of developing cataracts earlier or having them progress faster. If you have any of these risk factors and notice even mild changes in your vision, it’s worth getting an eye exam sooner rather than waiting for symptoms to become obvious.