The bifocal was famously invented by Benjamin Franklin in 1784. This invention was an efficient way of assisting those who need different levels of vision correction for different focal ranges. For example, those who need glasses to see things far away, but not close up. This was a much simpler alternative to keeping up with different pairs of reading glasses. Even now, these two options are still essentially the only two choices for those who require this type of vision correction.
For more than two centuries there have been few major changes to Benjamin Franklin’s invention. Many still struggle with the behavioral changes that are necessary to uses these lenses correctly. Even with the advent of progressive lenses, which provide a lineless gradient between prescriptions, users often must find a “sweet spot” to look through that will focus correctly for their short, near and intermediate ranges. Both types also naturally restrict your field of vision to only what can be seen through the section of the lens for that focal range.
There is now a possible solution that could eliminate all of these problems and open the door to a 21st century view of vision correction. An engineering professor and a doctoral student from the University of Utah have developed a pair of glasses that have the ability to detect and adapt their prescription automatically in real time. This would completely eliminate the need for reading glasses or bifocals entirely.
The glasses use a small infrared camera, similar to the ones used in the autofocus of digital cameras. The camera detects the distance of the object from the wearer, and uses small pistons to stretch the clear flexible membranes of liquid which make up the lenses. This stretching causes the lenses to become more concave or convex, which changes the prescription of the lens.
In order to get things started, the user simply inputs their current prescription into a smartphone app that is connected to the glasses via Bluetooth. This is communicated to the glasses which then makes the necessary adjustments to match that prescription. From there, the glasses make all of the necessary adjustments depending on where the user is looking. This also means that if the user has an eye exam and ends up with a prescription change, updating the glasses with that new prescription is only a smartphone app away.
This is a major improvement on the current system because it adjusts the prescription of the entire lens. This allows the wearer to move their eyes naturally within their full range of vision. Even if the object that is close requires the wearer to look through the top of their lens, the object will still be within focus. This all happens within a period of 14 milliseconds, so the user can freely look around and see everything in focus without missing a beat.
The benefits of this new technology extend well beyond just their benefits to bifocal and progressive users. It forces us to raise the bar on what how correct our vision correction can be. It also opens the door to a much higher level of sustainability with any pair of glasses being 3d printable and programmable to take any prescription.
The glasses are not quite ready to roll out as they are still in the prototype stage, and the researchers hope to refine the aesthetics and size now. Considering how long it’s been since the last major revolution in bifocals, its surely to land right on time, whenever that may be.
Read more about the discovery here: https://www.osapublishing.org/oe/abstract.cfm?URI=oe-25-2-1221