How Progressive Lenses Work

Also known as ‘no-line’ bifocals, eyeglasses with progressive lenses provide a smooth transition between lens powers for all distances.

In this post, you will find out about how progressive lenses work, their advantages over bifocals, when do you need to get glasses with progressive lenses as well as how to get used to them.

Progressive lenses vs bifocals

The term multifocal is an umbrella term for eyeglasses with lenses that include more than one optical power. As well as progressive glasses with multiple lens powers for all distances, there are bifocals with vision correction for two distances and even tri-focals for three different distances.

The most easily spotted difference between bifocals and progressive multifocals is the line on the lens. Bifocals have a visible line separating the upper portion (for distance vision, like seeing across the room) and the lower one (for close-range vision, such as reading), while progressive lenses look just like single-vision prescription lenses.

Bifocals are considered old and unfashionable. Progressive lenses are preferable style-wise, but the ability to see at all distances offers the biggest advantage.

How it works

A progressive lens is designed to include multiple optical powers to all distances: Near, intermediate and distance. There is no so-called image jump; instead, there’s a seamless transition between fields of vision, providing more natural focus and depth. Once you’re adjusted to them (more on that below), there’s no need of constantly moving your head and shifting your glasses to view things in the intermediate range (especially computers); instead, it’s a matter of looking through the right part of the lens.

The progressive lens has a vision corridor with different zones for each range. The distance viewing zone is at the upper part of the lens and usually wider than the intermediate and near zones. The lens and the vision corridor can be customized depending on need. The view through the peripherals of the lens appears blurry.

In the past, progressive multifocals required large frames to accommodate all viewing powers. Today however progressive lenses can be fitted on small frames just like single-vision prescription glasses, and the lens includes fewer peripheral distortion.

progressive

Who needs progressive lenses

Progressive multifocals are mostly used to correct presbyopia, an eye condition associated with aging which affects everyone to some degree from the age of 35. People with presbyopia find it difficult to focus on objects up close, and progressive lenses correct that, along with other refractive errors a person may have. They allow a person to use one pair of glasses, instead of switching between their reading glasses and single-vision (distance) frames back and forth.

Despite their association with middle-aged and older people, recent studies have shown that myopia (nearsightedness, the most common refractive error) can be slowed down in children who wear progressive multifocals.

Getting used to progressive lenses

Your first time wearing progressive eyeglasses take time getting used to. The transition between lens powers and the small aberrations on the peripherals of the lens require an adjustment period. It can be a matter of minutes, but it can take up to a few days and perhaps ever a few weeks in some cases. People with hyperopia (farsightedness) usually need more time to adjust to multifocal progressives than those who are nearsighted.

Here are a few tips that can help speed up the process of adjusting to a new pair of multifocals:

1. Try wearing your new progressive multifocals as much as possible (except for driving); it’ll help you get used to them more quickly.
2. Two of the most common complaints with new multifocals is having trouble reading and walking up stairs. Initially, move your head and not your eyes until you find a position that you’re comfortable with, which eventually becomes second nature. To read, look through the lower part of the lens. When climbing stairs, look straight ahead instead of glancing down.
3. When wearing progressive lenses, look through the center of the lens. Otherwise, objects will appear blurry.

Leave a Reply

Your email address will not be published. Required fields are marked *

You May Also Like