Heralded as a revolution by people who need glasses to read, laser eye surgery can eternally change your vision by reshaping the cornea. After a hinged flap is cut a portion of the cornea is revealed and exposed to laser pulses that vaporise the cornea and correct the shape permanently. This procedure can help myopic people suffering from sight-sightedness, and hyperopic sufferers with long-sightedness. However there is still the inevitable issue of age.

Presbyopia is the condition where our eye's ability to focus on close objects deteriorates. This occurs naturally as we get older and the crystalline lens' elasticity is reduced. Over time it becomes so rigid that it's beyond the control of the cornea, and therefore the eye muscles can't change the lens's shape in order to focus.

Now don't cancel your laser eye surgery appointment just yet but recent advancements in the field of vision are yielding some interesting results. Electronic bifocals look like something straight out of a Philip K. Dick novel and could have a ground breaking impact on the world of optical science. For anyone who requires bifocals you will know how frustrating it can be with a limited field of vision, being able to make out
objects at a distance but unable to distinguish things at too close a proximity and having to continually shift your line of sight to do so. Well imagine you could do it at the flick of a switch. That is the premise of the electronic bifocals being developed by Guoqiang Li and fellow researchers at the University of Arizona.

The prototype pair of glasses is a crude looking piece of kit with two black boxes containing the driver chip which are positioned on the frames by the wearer's ear. Each lens is made up of two flat glass plates sandwiching a shape-shifting layer of liquid crystal that is as thin as a single strand of human hair. When a current is activated by the user and runs through the electrodes, it causes the liquid crystals to change composition and simulate the close focusing power of the natural human eye lens. To alternate between one focus and the other the subject uses a switch on a mini battery pack that can be attached to a belt or concealed in a pocket. Soon, however, the creators are hoping to integrate sensors into the technology so a switch will no longer be necessary and the focus of the electronic bifocals with be automated.

It sounds the stuff of science fiction but the work being executed in Arizona is very real and could spell the future of vision and our window to the world.