The VR Technology Helps to Develop the Smart Reading Glass with Autofocusing Ability
As we age, we lose the ability to focus and the distance to objects becomes farther away. This is due to the loss of the ability of the lens to become flexible to bend and change its shape. As a result, the images we see appear out of focus. As a newborn, you would have been able to focus as close as six and a half centimeters. By your mid-20s, you have about half of that focusing power left. Presbyopia affects at least 2 billions of people, it is a condition that becomes noticeable in the early to mid-40s and worsens until around age 65.
Century Old Problems for Humanity
For centuries, presbyopia was corrected with the use of bifocal eyeglasses. The problem of bifocal lenses is that you lose field of vision at any given distance, because it gets split up from top to bottom. Top section is used for focusing far distance, and the bottom section is used for reading or shorter distance. If you’re climbing down a ladder or stairs, when you look down, it gets blurry because you are using the bottom part that focuses a short distance, but you need to focus on a far distance to safely walk down the stairs.
A Quest for A Solution
Smarter glasses are needed since none of these reading lenses fix the natural refocusing habit or needs for our daily lives.
1. In the past decades, we have developed three types of “focus-tunable lenses”
Mechanically-shifted Alvarez lenses
Deformable liquid lenses
Electronically-switched liquid lenses
2. By borrowing technology from virtual and augmented reality systems, we can build an algorithm to estimate focusing distance. We have an eye tracker device that can tell what direction our eyes are focused in. The combination of these two information, we triangulate your gaze direction and the focus estimate. Another distance sensor is also added to increase its reliability when reporting distances to objects.
In summary, by using and fusing these distance data, we can update the tunable lenses accordingly and give the smart glasses its autofocusing ability.
Looking to the future
The team at Stanford continues to improve its robustness of the eye-tracking solution, and hope in the near future, they can make the bulky experimental autofocus glasses that look like normal glasses.
