What is poor contrast sensitivity?

If you have low contrast sensitivity, you may have problems with night driving, including difficulty seeing pedestrians walking alongside poorly lit streets. Or you might notice that your eyes tire more easily while reading or watching television.

What does contrast sensitivity mean?

Contrast sensitivity is a measure of the ability of the visual system to distinguish an object against its background. A target must be sufficiently large to be seen, but must also be of high enough contrast with its background. A light grey letter will be less well seen against a white background than a black letter.

What is normal contrast sensitivity?

Norms for different levels of contrast loss include profound loss at less than 0.48 log contrast, severe at 0.52-1.00, moderate 1.04-1.48, normal for individuals older than 60 years is 1.52-1.76 and normal for individuals age 60 and younger is 1.72-1.92 log contrast.

What affects contrast sensitivity?

Contrast sensitivity is also influenced by pupil size. Changes in pupil size negatively affect contrast sensitivity at both ends of the spectrum. It has been suggested that contrast sensitivity is reduced by diffraction with a miotic pupil, and possibly by spheric aberrations with a dilated pupil.

What does contrast sensitivity look like?

A sine-wave grating test is a more sophisticated contrast sensitivity test. You will look at several parallel, fuzzy bars of dark and light. This test provides a more sensitive way to see how your eyes view contrast. Once low contrast is diagnosed, the doctor will determine which type you are dealing with.

Why is contrast sensitivity function important?

The contrast sensitivity function has the potential of adding more information about the functioning of the visual system than that given by visual acuity, because it assesses sensitivity over a wide range of spatial frequencies, while visual acuity measures primarily sensitivity at the high spatial frequencies.

Is high or low contrast better for eyes?

Human eyes distinguish the best if white appears on a black background and vice versa. Hence, the contrast ratio should be higher for the eyes to lessen the stress on the eyes. Try to avoid low contrast color schemes as they are stressful and result in eye strain and fatigue.

How does macular degeneration affect contrast sensitivity?

For the patients with AMD, the loss of contrast sensitivity was most pronounced in the lower spatial frequency range. The mean peak of the curve was only 21, whereas it was 89 for the healthy volunteers. Looking at individual spatial frequencies, the difference was significant (p<0.05) at 15 cycles/deg and lower.