What Are Varifocal Lenses?

How Varifocal Lenses Work

Varifocal progressive lenses use a simplistic design since they're single-vision lenses. They work by providing gentle, gradual changes of visual distance in different parts of the lens material: Distance vision at the top, intermediate vision in the center, and near vision at the bottom of the lens. You can see at varying distances depending on where you look in the lens. The seamless transition between vision distances makes for a higher-quality vision correction experience.

This design, however, has some drawbacks, as it can take time for your brain to adapt. Because no visual lines in the lenses help guide your eyes to the magnification you need, you must train yourself to know where to look. For instance, you'll need to look down at the right spot for reading, straight ahead for distance, and between those two areas for intermediate distance or computer work. During this eye- and brain-training process, you may experience symptoms including eye strain, headaches, dizziness, and nausea.

Getting Used to Wearing Varifocals

Getting used to varifocal glasses can take some time. Here are some ways to help you adapt to using varifocal lenses. First, don't move your eyes to see at all distances. Instead, rely on your head movements and point your nose where you need to look. Second, don’t be discouraged. Give yourself time to adapt. It might take days or even a few weeks for you to get used to the varifocal lens change. Lastly, 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 Lenses vs. Bifocal and Trifocal Lenses

In contrast to varifocals, which have magnification changes gradually throughout the lenses, bifocals and trifocals have two and three visual magnification areas respectively, divided by strict "transition lines." These changes can cause something called an "image jump," where what you're looking at can quickly alter in clarity and apparent position as you look across the prescription lines in the lenses. Bifocals correct both close-up and far vision, with one line (which is sometimes visible, sometimes not) dividing the lens. To see close up, you look into the bottom of the lens. To see into the distance, you look out the top area of the lens. Trifocals have three visual magnification areas: close-up, mid-range, and far vision. You look into the bottom, middle and top parts of the lenses, respectively, for those different visual areas.

Another difference between the lens types can be cost: Varifocal lenses can be more expensive than bifocal and trifocal lenses due to their unique single-lens design. Depending on your individual needs, your eye doctor can help you decide which type of lens works best for you. With the many advantages that varifocals offer, they might be the right option — but keep in mind that they do have drawbacks. Discuss these choices, and what you're looking for in lenses to treat your presbyopia, with your doctor today.