Telescopic Contact Lenses Zoom and Enhance

By Wesley Fenlon

Optical zoom in a contact lens? It's possible, and may lead to new lens technology to offset macular degeneration.

If only real life worked like CSI, we'd constantly be able to shout "Enhance!" to correct our vision, zoom in on a blurry object in the distance, and sharpen it into perfect relief. Instead, we squint, or put on glasses, or even use binoculars to make out a distant object. But what if--what if--you could zoom in on anything around you using only the power of you eyeball? Science has conspired to make it so with a telescopic contact lens, which adds a 2.8x zoom to your eyeball.

The center region of the contact provides normal, unmagnified vision, so you're not walking around all the time with one (or both) eyes uncomfortably zoomed in on your surroundings. But around the outside of the lens, vision is magnified 2.8x times. Bifocals for your eyeballs.

The real breakthrough with this lens is its 1.17mm thickness, which is thin enough to be worn. For comparison, soft contact lenses are typically less than 0.2mm thick. Rigid lenses are thicker, sometimes up to 0.5mm. Clearly this telescopic lens is thicker, and no doubt less comfortable, than the lenses millions of people wear every day.

But even getting the telescopic lens to that wearable degree of thickness was a challenge. And this prototype, despite being impressive, is still pretty limited--you have to wear it with a pair of 3D glasses, and it doesn't offer the full field of view of normal human vision. But there are real benefits here for sufferers of macular degeneration, which is what this telescopic lens is currently aimed at. Our willy-nilly ENHANCING comes later.

So how does it work, exactly?

Light is bounced around a set of four aluminum reflectors and magnified. The study adds more detail: The magnified path incorporates a telescopic arrangement of positive and negative optical power to achieve 2.8x magnification on the eye, while a central clear aperture provides unmagnified vision. The dual optical paths make it possible to switch between unmagnified and magnified vision by selective blocking of the central and annular aperture. We have chosen a polarization approach to make the view switchable; using orthogonal polarization films over the apertures combined with a pair of off-the-shelf switching liquid crystal (LC) glasses made for 3D television."

The researchers still have work to do; they note that image quality didn't meet their expectations, but they know why, and are working to improve the lenses in ongoing research. Additionally, the lens is made from a gas-impermeable material called PMMA, which lenses have moved away from. Since the 1970s, RGP, rigid gas polymers, have become more popular, and the researchers hope to switch to that material for a future lens.