When Salvino d’Armate invented eyeglasses circa 1285, he probably couldn’t have imagined that his invention would still be helping people in the twenty-first century. Roughly sixty-four percent of the world’s population wears eyeglasses, though the frames are no longer made of bone and the lenses are no longer made of quartz.
Likewise, when California optometrist, Kevin Tuohy , invented gas permeable corneal contact lenses in 1948, after many less effective designs had been invented by many predecessors, perhaps he couldn’t have imagined that his design would one day help eleven percent of the population worldwide. Glasses and contact lenses are very effective vision aids for people who have visual impairments. However, their effectiveness is limited for those who have vision-related disabilities, such as low vision.
In 2015, the American Association for the Advancement of Science revealed a new type of contact lens designed for people with low vision. Eric Tremblay, the head of a team of designers at the Swiss Federal Institute of Technology, believes it will be especially effective for people who have macular degeneration, a condition in which someone gradually loses his or her central vision. Larger and more rigid than a standard contact lens, Tremblay’s lens covers the sclera of the eye.
Small aluminium mirrors are arranged around each lens’ center. The mirrors bounce any light that streams through the lens, causing the light to magnify any objects in the wearer’s vision to 2.8 times their normal size. Users can switch between magnified and normal views by wearing the contact lenses in conjunction with a pair of electronic glasses.
Wink with one eye, and the glasses switch to a polarized filter that directs light to the telescopic part of the lens. Wink with the other eye, and the setting switches, allowing light to pass through the lens normally. This design is an improvement of an earlier prototype, which did not include the toggling feature. In addition, the current design includes small channels to allow oxygen to flow around the underside of the lens. Otherwise, a wearer could only use the contact lenses for a limited time, since the large, thick lenses would limit airflow to the eye.
Clinical trials began in 2018. A clinical trial is a research study to evaluate the effect a particular medical, surgical, or behavioral intervention has on humans. If the intervention is found to be safe and helpful, it may be approved for commercial release. Even though the toggle lenses aren’t yet commercially available, scientists are already hoping to develop contact lenses that could help people with other medical conditions.
These include contact lenses that could check for glaucoma and contact lenses that could check their user’s glucose level. The latter would be marketed to people who had both a visual impairment and diabetes.Even if the toggle contact lenses are safe and effective, not everyone who has a vision-related disability will be be able to use them. Some people who are physically disabled may have difficulty winking or be unable to take the contact lenses in and out without assistance.[H/T MyModernMet, NewScientis]