How Varifocal Lenses Work

Since a varifocal progressive lens is a single lens, it utilizes a simplistic design. They work by providing gentle, gradual changes of visual distance throughout the lens material. Distance vision is at the top of the lens, intermediate vision in the center of the lens, and near vision is at the bottom of the lens. You can see at varying distances depending on what parts of the lens you look through. While varifocal lenses have a very sophisticated design, the design has some drawbacks. First of all, it can take time for your brain to adapt to how the lens is made. Because there aren’t any visual lines in the lenses to help guide your eyes to the magnification you need, you must train yourself to know where to look. For example, you'll need to look down through the bottom of the lens for reading, straight ahead for distance, and between those two areas for intermediate distance. During this time when your eyes and brain are getting acclimated to the varifocal lenses, you may experience symptoms including eye strain, headaches, dizziness, and nausea.

Tips for the Varifocal Lens Learning Curve

Here are some tips to make the transition to wearing varifocals easier:

• Don't move your eyes to see at all distances. Instead, move your head and point your nose where you need to look.

• Give yourself time to adapt. It might take days, or even a few weeks, for you to get used to the varifocal lenses.

• Don't give up — keep wearing them (though you can take them off briefly to give yourself a break). If you're struggling, contact your eye doctor for further advice.

Varifocal vs. Bifocal and Trifocal Lenses

In contrast to varifocals, which have seamless magnification changes throughout the lenses, bifocals and trifocals have two and three visual magnification areas respectively. These are divided by visible "transition lines." Looking across the prescription lines in the lenses can cause something called an "image jump.” This is when what you're looking at can quickly alter in clarity and apparent position.

• Bifocals: These help both close-up and far vision. There is one line, which is sometimes visible and sometimes not, that divides the lens. To see close up, you look through the bottom of the lens. To see into the distance, you look through the top area of the lens.

• Trifocals: As you might expect from the "tri" part of the word, trifocals have three visual magnification areas: close-up, mid-range, and far vision. You look through the bottom, middle, and top parts of the lenses, respectively, for those different visual areas.

Cost can be another big difference. Varifocal lenses can be more expensive than bifocal and trifocal lenses due to their unique single-lens design.