Background

The lens has its maximal flexibility when we are young. As we age, the lens becomes more rigid. Since the flexibility of the lens is crucial to accommodation, this loss of flexibility causes us to lose some of our ability to accommodate. More specifically, we lose the ability to thicken the lens so we can see more closely. As a result, we lose the ability to see close objects clearly, leading adults to need extra aids to read—reading glasses, bifocals and the like.

Instructions

Full Screen Mode

To see the illustration in full screen, which is recommended, press the Full Screen button, which appears at the top of the page.

Illustration Tab

Settings

Below is a list of the ways that you can alter the illustration. The settings include the following:

Light Position: moves the light closer or farther from the eye.
Turn Light On: Pressing this button will start the light. Pressing the button again removes the light.
Make Eye Presbyopic: When checked, the lens of the eye becomes presbyopic.

Reset

Pressing this button restores the settings to their default values.

Try these settings to see how presbyopia effect accommodation


Make Eye Presbyopic

Currently the eye accommodates like a young person's eye. The eye can focus clearly at all distances.

If you have not yet examined accommodation, please do so now. When you are young, your lens has its maximal flexibility allowing you to focus at both near and distant objects. As you age, the lens stiffens in a way that it focuses best at distant objects. Make the eye presbyobic to see how focusing becomes limited to distant objects as we age.

Proceed to Quiz