One of the most commonly asked questions in an eye exam comes right after the refraction, or glasses prescription check: “What is my vision?”

Almost invariably, people know the term “20/20”. In fact, it’s a measure of pride for many people. “My doctor says I have 20/20 vision.” Or, on the other side of that same coin, having vision that is less than 20/20, say 20/400, can be a cause of great concern and anxiety. In this discussion I will describe what these terms actually mean.

To lay...

Diabetic retinopathy is an eye condition that can affect the retina of people who have diabetes.

The retina is the light-sensitive tissue that lines the back of the eye, and it detects light that is then processed as an image by the brain. Chronically high blood sugar or large fluctuations in blood sugar can damage the blood vessels in the retina. This can result in bleeding in the retina or leakage of fluid.

Diabetic retinopathy can be divided into non-proliferative or proliferative...

A refraction is a test done by your eye doctor to determine if glasses will make you see better and what your prescription is.

The charges for a refraction are covered by some insurances but not by all.

For example, Medicare does not cover refractions because they consider it part of a “routine” exam and Medicare doesn’t cover most “routine” procedures--only health-related procedures.

So if you have a medical eye problem like cataracts, dry eyes, or glaucoma then Medicare and most...