A new type of eyeglasses can shift focus from distant objects to nearby ones, helping presbyopic individuals see more clearly. This product is expected to replace the current bifocal glasses and address other vision issues soon.
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These eyeglasses will shift focus from distant to nearby objects and may replace bifocals within the next 2-3 years. (Image: Discovery) |
The product is called the electronic diffractive lens, developed by researchers at the University of Arizona in Tucson and Georgia Institute of Technology in the United States.
According to the researchers, 93% of people over 45 need some form of reading glasses to correct presbyopia. In this condition, the eye’s lens gradually loses its elasticity, diminishing its ability to increase curvature to focus light. People with presbyopia can see distant objects but require glasses to see nearby ones.
Bifocal glasses are a familiar solution, but they also mean a divided field of vision. Another solution called monovision uses contact lenses for one eye to see far and the other eye to see near. Over time, the brain learns to use the appropriate eye for the task. Both methods are not ideal and can cause nausea or dizziness.
The new glasses utilize a small electric charge to create precise light focus across the entire lens. “Users can observe objects using the entire field of view of the lens,” said Gouqiang Li, assistant research professor at the University of Arizona and the lead researcher.
The glasses consist of a thin layer of liquid crystals—similar materials used to create computer screens—sandwiched between two glass plates. Each glass plate is coated on the outside with a transparent electrode made from indium tin oxide, and one plate has an etched outer layer creating a series of concentric circles.
Light passing through the glasses will be diffracted and obstructed by the concentric rings, directing the movement of molecules within the liquid crystal layer.
By applying a voltage to the electrodes to change the direction of the molecules, a different focal point can be achieved. This voltage can be adjusted to obtain the desired focus.
Currently, the prototype of the new glasses is controlled between on and off states.
“The challenge of this unique technology is that it still creates a view that is either all or nothing. Users tap a switch lightly, and it will shift the focus from far to near. It does not allow them to see both far and near simultaneously,” said Mark Bullimore, assistant professor at the Ohio State University College of Optometry.
A company has purchased the patent to commercialize this technology, which may be available in the next 2-3 years.
T. An
