What is contrast sensitivity? (Posted: jan 2005)

Technically, it is the ability to perceive the difference between an object and its background. Practically, it is the ability to sort through your sock drawer in moderate lighting or the ability to see faces reasonably clearly in a restaurant.

How does laser eye surgery affect contrast sensitivity? (posted: jan 2005)

Generally speaking laser eye surgery is believed to reduce contrast sensitivity. This can occur in degrees small enough to be barely perceptible or large enough to be disabling. There are a few different mechanisms involved which will be discussed in separate articles.

What does reduced contrast sensitivity mean for the patient? (posted: jan 2005)

Reduced contrast sensitivity can make all activities in anything but bright sunlight much more difficult. Classic examples are any environments with fluorescent lighting (supermarkets, airports, etc) which pose major vision problems to patients with reduced contrast. Basic tasks in the home may be affected. Patients with reduced contrast often have to install halogen lighting in places where they perform tasks such as ironing or reading. Even safety can become an issue as patients with poor contrast may not see steps or curbs in time. Recognising faces is another classic example of a contrast problem.

How is it diagnosed? (posted: jan 2005)

There are several different types of contrast sensitivity testing, any one of which can identify moderate to severe contrast problems. These include the Pelli-Robson test, the Regan chart, and Ginsburg's FACT test.

Can it be treated? (posted: jan 2005)

Gas permeable contacts may at least partially restore contrast sensitivity. Additional laser surgery may or may not bring benefits but if it does it is typically limited.

Where can I learn more about contrast sensitivity? (posted: jan 2005)

Click here for Encyclopedia entry, which may have additional articles and links.