When a cataract first develops, it can’t be seen without special instruments. But as it grows, a cataract can cloud your lens, making the world look hazy and less colorful.
A cataract is a change in the eye’s lens that can cause blurry vision and potentially severe vision loss.
Early on, a cataract can only be seen with the instruments an ophthalmologist uses during a thorough eye exam. But if left untreated, a cataract can make your lens look cloudy and alter the appearance of the pupil, the normally dark hole in the center of the colored iris.
Despite the serious impact cataracts can have on your vision, they can be treated successfully with surgery to remove the affected lens and restore clear vision with an artificial lens implant.
Because cataracts can develop slowly, regular eye exams can lead to an early diagnosis, which can result in earlier treatment and a lower risk of any vision complications.
A cataract is a clouding of the lens that eventually affects your vision. The National Eye Institute reports that
Aside from age-related cataracts, other types and causes include:
- congenital cataracts present at birth
- diabetes-related cataracts, which can occur when high levels of circulating blood glucose (sugar) harm the lens of the eye
- radiation cataracts, which may develop from too much ultraviolet light exposure from the sun or cancer treatment
- toxic cataracts, which can arise following exposure to certain chemical substances or as a side effect of certain medications
- electrical cataracts, which can appear immediately following a lightning strike or from accidental electrical current passing through the body
- secondary cataracts that can sometimes develop after cataract surgery
- traumatic cataracts that develop after an injury to the eye
You can read more here about cataracts in general.
In their early stages, cataracts are not always visible by looking in a mirror. As a cataract develops, you may see a white or bluish-white clouding form in the pupil. As time goes on, the clouding appears denser and thicker.
Congenital or cataracts in children appear differently. Parents often observe a discrete white speck in the child’s pupil. Sometimes, the entire lens will become frosty white and visible.
A cataract that forms due to type 2 diabetes may look like a snowflake or starburst. A traumatic cataract looks like a clouded lens on part of the eye, while injury to the iris or other part of the eye may also be visible.
Cataract surgery can be performed before the cloudy lens becomes visible to others.
As a cataract starts to form, you may have no vision changes. And because a cataract can grow slowly, any changes in your eyesight may develop slowly without you realizing them at first. In time, your vision will start to blur, and colors will lose some of their vividness.
You may have no vision problems, but an eye exam in which the eyes are dilated may detect a cataract in its early stages.
An ophthalmologist will use an instrument called a slit-lamp microscope to get a detailed look at the lens, cornea, and iris. This may help detect a cataract long before it causes any vision changes.
While the lens may become cloudy and turn a whitish-blue color as a cataract matures, the iris, or colored part of the eye, will keep its original color. That color will remain the same after cataract surgery, too.
Vision changes triggered by cataracts usually start slowly. Images may appear a little blurry or hazy, especially in the central part of your field of vision. You may notice that objects appear dimmer and less vivid, and that colors take on a yellowish tint.
Other cataract symptoms include:
- difficulty with night vision
- double vision (especially as cataracts worsen)
- headlights, lamps, and other lights appear abnormally bright
- seeing a “halo” around lights
If not treated, cataracts may ultimately cause irreparable vision loss.
When to seek medical care
If your cataracts aren’t causing any vision problems, you may not need to do anything right away. However, waiting too long to have cataract surgery can make the procedure riskier and more difficult.
The American Academy of Ophthalmology recommends that a new eyeglasses prescription may help you overcome vision changes triggered by early cataracts. But you should still strongly consider surgery when cataracts affect your vision so severely that you can’t drive or manage everyday activities.
By the time you notice a clouded lens, your cataract has probably been developing for a long time. It may not be too late to have the affected lens surgically removed and replaced with a new lens. A new lens may not only clear up your vision but may help improve your eyesight.
Cataracts are very common and treatable. The best way to avoid having a cataract cause permanent or even temporary vision problems is to have regular eye exams that include dilation and a close look at all the different structures inside the eye.