Types

What Are Cataracts?

Choose a preferred language

The lens in the eye focuses light so the eye sees images sharply. Aging is the most common cause of cataracts. With age, the lens slowly becomes cloudy. The cloudy lens is a cataract. A cataract scatters light and makes it hard for the eye to focus. Cataracts usually form in both eyes. But one lens may cloud faster than the other.

Three-quarter view of eye showing lens sharply focusing light. Three-quarter view of eye showing cataract scattering light.


The aging of your lens

Your lens may cloud so slowly that you don`t notice any vision changes at first. But as the cataract gets worse, the eye has a harder time focusing. In early stages, glasses may help you see better. As the lens gets more cloudy, your healthcare provider may advise surgery to restore your vision.

A clear lens allows your eye to bring objects sharply into focus.

A mild cataract may slightly blur your vision.

A dense cataract can severely blur your vision.

Online Medical Reviewer: Chris Haupert MD

Online Medical Reviewer: Marianne Fraser MSN RN

Online Medical Reviewer: Raymond Kent Turley BSN MSN RN

Date Last Reviewed: 09/01/2025

© 2000-2026 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Find a Provider

View Our Directory

Find a Location

View Our Practices
Related Articles
Read article
Eye Care
Meibomian Gland Blockage

The meibomian glands are small glands located inside the upper and lower eyelids. They secrete oils that work with tears. If your meibomian glands become blocked by thickened oils, your eyes will become dry. Your eyes may feel irritated.

Read article
Eye Care
Retinal Tear

With age, the gel that fills the eye contracts, and can tear the retina. This causes floaters and flashes of light. It can lead to retinal detachment and vision loss.

Read article
Eye Care
Eye Bruise (Contusion)

An eye contusion (bruise) can cause pain and swelling around the eye. The skin may also change color.

Read article
Eye Care
What Is Blepharitis?

Blepharitis is a redness and swelling (inflammation) of the eyelids. The membrane covering the inside of your eyelid and the white of your eye may also become inflamed. It can’t always be cured. But it can be controlled.