From bifocals to future autofocals

Lifelong learning is a goal deemed worthy by many people. Learning and reading go hand in hand. Like our knees, our eyes are made keenly aware of the passage of time and the gradual loss of vitality, thus putting a damper on our desire to read and learn.

As we age, it gets harder and harder to read, because of a condition known as presbyopia or farsightedness. A newborn baby can focus on an object as near as 6.5 cm away or 2.5 inches. By middle age. the closest a person can focus is 25 cm or 9.8 inches, almost 300% worse than at birth.

Technology has always been used to mitigate the declining eyesight due to age. First, there were reading glasses or single-vision glasses. Wearers of reading glasses can read at a comfortable near distance but they need to remember to bring a pair with them everywhere. When they are not actively reading, it is uncomfortable enough that they would want to take it off. The constant putting on and taking off of reading glasses can become a self-conscious socially embarrassing behavior for presbyopics.

The invention of bifocals and progressives addressed the above shortcoming of reading glasses. With bifocals, wearers read by looking downward through the bottom portion of the lenses. When not reading, they can get by seeing through the top portion. While bifocals, the glasses with the ‘ugly’ lines, are functional, they are not the typical fashion statement that most people want to make. Aesthetics aside, many loathe the wearing of bifocals for the associated real or perceived social stigma.

Progressive lenses removed the telltale lines by seamlessly transitioning from distance viewing through the top portion of the lenses, to computer work through the middle portion, to reading through the bottom.

While progressives are a definite improvement over reading glasses and bifocals, there is a significant hidden risk that are of particular concern to older wearers—the risk of falling, not the glasses, but the owner.

When one climbs stairs, it is natural and essential to watch one’s steps, meaning looking down. A person looking down while wearing progressives (bifocals too) will see blurry images of the immediate steps because it is too far. Given that falls are the leading cause of injury-related visits to ER in the USA for people over 65, wearing progressives has its own significant downside for baby boomers.

The inherent problem with progressives (and bifocals) is that they are static, fixed to focus a certain way depending on which part of the lenses the wearer is viewing. Researchers are busy at work to come up with the next generation of presbyopia-correcting lenses, namely ‘autofocals’ or focus-tunable lenses.

Autofocals promise ‘full-field-of-view vision that can be sharp at any desired distance.’ Autofocals use eye tracking technology to track the wearer’s gaze direction in order to triangulate the intended vision focus point, regardless of distance. Like the camera lens from your smartphone, except you wear it as a pair of glasses.

For more details, please watch the above TED talk by Nitish Padmanaban, a Stanford researcher.

After reading this post, many people will want to head out to the nearest eyewear store to buy a pair of autofocals. The good news is that Nitish Padmanaban and several others have formed a start-up company to commercialize the technology. The bad news is that the technology is not quite ready to roll out yet.

What the researchers have as of now is a prototype. It is bulky and ugly. Imagine wearing something that resembles a phoropter, the device used for your eye exam, except you will be wearing it outside the optometrist office.

In the meantime, we wish Nitish Padmanaban and his colleagues good luck in bringing autofocals from the laboratory to the eyewear store.

Leave a Reply

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