Since bifocals were first invented in the late 18th century, the technology behind them hasn't changed too drastically. Now an Israel-based start-up is working on a new type of lenses that use smart tech to automatically adjust their focus based on what you're looking at, MIT Technology Review reports. 

The company, called Deep Optics, has spent the past three years developing their Omnifocals. When people wearing the glasses aren't looking at objects up-close, the lenses default to focusing on objects farther away like a regular pair of glasses. The moment the wearer moves their eyes to look at something closer like a book or a phone screen, sensors built into the frame measure the distance between the pupils and send the data to a mini processor. The processor then uses this information to adjust a special liquid-crystal layer in the lenses so that it refracts light accordingly. 

This type of technology could be especially helpful for with people with presbyopia, which is the same condition that inspired Benjamin Franklin to create himself a pair of bifocals. This vision problem commonly affects people as they age, making it more difficult for them to focus on objects that are closer. Many people with presbyopia wear eyeglasses with progressive lenses that require looking through the exact right spot to focus clearly. These new types of lenses self-adjust within a fraction of a second without requiring any extra effort from the wearer.

While the glasses are still in the prototype stage, a commercial version could be coming sometime in the future; the company expects to have people begin to test them "extensively" in about two years, CEO Yariv Haddad told MIT Technology Review. Deep Optics recently announced that they have $4 million in venture capital to make their vision a reality, thanks to investors like the French glasses company Essilor. Besides the eyeglasses industry, the technology could also be of interest to virtual-reality headset manufacturers looking to make their users less prone to motion-sickness.

[h/t MIT Technology Review]