While solar power is one of the leading sources of renewable energy available to us, it’s easy to argue that we have a long way to go in terms of directly harnessing the sun’s rays. For instance, most solar devices in our daily lives must be hooked up to a battery or capacitor in order to store the energy they derive. A novel invention from the University of Wisconsin, Madison solves this issue by keeping solar energy readily available in the mechanism itself. But most impressive of all is that the mechanism itself is a pair of solar contact lenses.
A reasonable inquiry to make at this point is why one would even need solar contact lenses in the first place, besides the obvious reason that they’re really cool. We answer with the natural phenomenon of eye aging called presbyopia, which plagues many adults over the age of forty. According to the American Optometric Association, presbyopia causes the crystalline lens of the eye to lose its flexibility, making it difficult to focus on close objects. However, the lens gets more rigid with time, so the ADA advises that “periodic changes in eyewear may be necessary to maintain clear and comfortable vision.”
The solution that UW bioengineer Hongrui Jiang presents is a solar powered contact lens that reforms to your eye as it increases in rigidity. This way, you only have to buy the one pair of contacts, and that pair always focuses the perfect amount. Now while the idea sounds good in theory, recall what we said before about solar devices always requiring a battery to hold their charge when the sun’s not out. This would be problematic at the scale of a contact lens, as we simply don’t have batteries that size that can hold any meaningful amount of charge.