SIGNS AND SYMPTOMS
CATARACTS SYMPTOMS
Not all cataracts produce the same symptoms. The type of cataract you have will determine the type of symptoms you may notice.
Clouded, Blurred, or Dim Vision
Cataracts on any part of the lens can cause fuzzy vision, but posterior subcapsular cataracts are likely to do so earlier in their development, as mentioned. As you'll recall from chapter 2, a posterior subcapsular cataract is located just beneath the capsule at the back of the eye, near the retina, where the area of incoming light is smallest. The cataract might not be very big, but it obstructs the cone of light at its narrowest point.
Nuclear cataracts, at the center of the eye, are directly in the path of incoming light. At first, nuclear cataracts, being thicker than the natural lens, might act like a magnifying glass, making close-up objects clearer. This short-term improvement in near vision, called second sight, is lost as the cataract worsens.
Halos and Glare
Bigger pupils create a larger pathway for light entering the eye, so more of the lens-including the edges of cortical and subcapsular cataracts-is exposed. When sudden bright light-car headlights, even street lighting and stoplights-enters the eye, the exposed cataract edges "scatter" it, causing halos and glare. A halo is a circle of light around a light source. Glare is light that dazzles and seems almost blindingly bright.
You've experienced this scattering of light when you've driven at night with a fogged-up windshield. The tiny drops of moisture on the window bend the incoming light in multiple directions, nearly blinding you with glare and making it very difficult to see where you're going.
Sensitivity to glare can occur with all types of cataracts. In general, glare is less troublesome for people with nuclear cataracts than for those with cortical cataracts. Posterior subcapsular cataracts usually produce the worst glare.
Some people find glare to be not only inconvenient but almost painful. If cataracts are making you extremely sensitive to glare and interfering with your day-to-day activities, discuss the possibility of surgery with your eye doctor.
Loss of Contrast
Scattering of light inside the eye also causes loss of contrast, making it hard for you to distinguish the edges of dark objects alongside lighter-colored ones. You might not be able to clearly see black lettering on a white page, or trees silhouetted against a bright sky.
Ghost Images and Double Vision
The tendency of cataracts to scatter light entering the lens can also cause double vision, especially if you're looking at a light source. Ghost images are similar to "seeing double." With double vision, however, you'll see two relatively clear images, whereas ghost images are fainter "copies" that appear on one side of or around the object you're looking at.
Just as we are either right-handed or left-handed, we also have a dominant eye. Ghost images and double vision usually affect the dominant eye more than the weaker one.
Difficulty Seeing in Bright Light
In bright light the pupil becomes smaller, narrowing the pathway through which light enters the eye. A nuclear cataract located in that pathway is more likely to obstruct your vision when your pupils are constricted and the pathway is narrow.
Change in Color Vision
Age-related cataracts become grayish or yellowish as they thicken. Naturally, these tints affect your ability to distinguish colors. It's common for people with cataracts to report that colors look washed-out, faded, or yellowish.
Dealing With Early Cataract Symptoms
