What is a cataract?
A cataract forms when proteins in the eye's clear lens break down and clump, clouding vision. Most are age-related—more than half of Americans have one or have had surgery by age 80—and diabetes, UV exposure, smoking and long-term steroids speed them up (Liu et al., 2017).
What are the symptoms, and how do cataracts differ from glaucoma?
Vision gets foggy, headlights cause glare and halos at night, and colors look faded or yellowish. Some people temporarily read better without glasses ("second sight"). Unlike glaucoma, which permanently damages the optic nerve, cataract vision loss is reversible with surgery.
When to have surgery and which lens to choose
No eye drop reverses a cataract. When it interferes with driving or reading, surgeons remove the lens by phacoemulsification and implant an intraocular lens (IOL). Monofocal lenses are covered by Medicare; multifocal or extended-depth-of-focus lenses reduce dependence on glasses but cost extra and may cause halos.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- When is the right time for cataract surgery?
- When cloudy vision affects daily life, such as night driving. There's no need to wait for it to be "ripe."
- Can cataracts come back?
- No, but a membrane behind the lens can cloud later; a quick YAG laser fixes it.
Sources reviewed: 2026-10-25
References
- Liu, Y.-C., Wilkins, M., Kim, T., Malyugin, B., & Mehta, J. S. (2017). Cataracts. The Lancet, 390(10094), 600–612.