Seeing the cataract
The lens sits behind the iris, so the pupil is dilated with drops and the lens is examined with a slit lamp, a microscope that shines a thin beam of light through the eye's structures. A cataract appears as a clouding, yellowing or spoke-like opacity in the lens. Its location and density are graded on standard scales, which allows change to be tracked from one visit to the next.
The types of cataract
- Nuclear cataract: the center of the lens hardens and yellows. The most common age related type; it blurs distance vision, dulls color and can temporarily improve near vision as it develops
- Cortical cataract: spoke-like opacities from the edge of the lens inward. Causes glare and light scatter, especially at night
- Posterior subcapsular cataract: a plaque at the back of the lens. Develops faster, affects reading and bright light vision early, and is more common with steroid use and diabetes
Many patients have more than one type, and the mix predicts which symptoms bother them most.
Measuring the effect on vision
A letter chart in a dim room understates what a cataract does. Glare testing repeats the vision test with a bright light source, reproducing headlights and sunlight, and often reveals a much larger loss. Contrast sensitivity testing shows the loss of definition that patients describe as 'washed out' vision. These results, more than the appearance of the lens, are what decide whether surgery will help.
Ruling out other causes
Blurred vision in a patient with a cataract is not always caused by the cataract. The examination checks the cornea for dry eye and dystrophy, the macula for degeneration or swelling, and the optic nerve for glaucoma, with imaging where needed. If another condition is contributing, it affects both the expected result of surgery and the choice of lens, and you will be told so before any decision.
Early cataracts
Most people over 60 have some lens change, and an early cataract is not a reason to operate. The diagnosis is recorded, your prescription is updated if that helps, and the lens is re-examined at your annual visit. Surgery is offered when the cataract is affecting what you want to do, not when it reaches a particular grade.
Is this right for your eyes?
Nothing on this page is a diagnosis. Whether this is the right choice for you is decided by a full examination at one of our 4 offices: Pasadena, Huntington Beach, Woodland Hills and Beverly Hills.
About this content: This page was written with the assistance of AI tools and reviewed for medical accuracy by Dr. Bavand Youssefzadeh, DO. It is general information, not medical advice, and does not replace an eye examination. Individual results vary. Read our medical disclaimer.
