WHAT IS MYOPIA & WHAT HAPPENS WHEN IT PROGRESSES?

When your child is myopic (which leads to nearsightedness), it means that distant objects are blurrier than near objects. To understand why this occurs, let’s first consider how a perfect eye works.

Consider when conditions are perfect:

When light passes through the clear, front window of the eye (cornea), it is focused on the inner lining of the eye (retina). Here’s an analogy (Figure 1): think of the cornea as a movie projector, with the retina as a projector screen. The projector and the screen are 20 feet apart, and the projector casts its image 20 feet away onto the screen. The result is a clear image.

Consider when the conditions are imperfect:

A nearsighted eye is longer, which causes light to focus in front of the retina instead of directly on it, leading to a blurry image (Figure 2). Imagine the projector casting an image 20 feet away, but with the projector screen now sitting 25 feet away, which leads to a blurry, out-of-focus picture. 

Below is an animated video describing the above concepts:

For the next in this series, titled “Is Myopia Unhealthy,” please click here to learn more.