Glasses and contact lenses that correct the vision of people suffering a common form of age-related sight loss are being developed by scientists.

A Nobel Prize-winning chemist has discovered a way to compensate for the distorted vision experienced by people suffering from age-related macular degeneration.

Damage to the retina causes their sight to become blurry and distorted. Over time they can become completely blind.The condition affects more than 460,000 British people. Prof Walter Kohn of the University of California, Santa Barbara, who won the Nobel Prize for chemistry in 1998, has developed a device that can correct vision to normal.

Using complex algorithms he can produce personalised lenses that compensate for the distortions, and is developing spectacles and contact lenses. He is also developing glasses that use tiny computers to display a corrected image from cameras on the inside.

Prof Kohn presented his device to the Lindau Nobel Laureate Meeting earlier this month.He believes it may be possible for patients to wear a device behind the ear to apply electrical currents to the nerve from the eye to the brain correcting distortions.

He said: “Macular degeneration is a very complex disease, but there is one feature that is present in almost all cases – visual distortions that cause straight lines to twist and curve.

“Each patient has their own personal distortion and they are a great hindrance for every day life. Walking up steps, for example, becomes hazardous. “I have formulated a way of correcting this using algorithms so we can correct the image on a computer screen for example or produce optical lenses for devices like spectacles.

“The lenses we are talking about are much more complex than those used to correct other eyesight problems like short-sightedness. We have to eliminate the distortions in macular degeneration with a complex compensation. “We would perhaps want to re-examine the patient’s eye once every six months to a year to update the device.”

There is currently no treatment for age-related macular degeneration. Early intervention to prevent scarring that can occur in the rarer form, known as wet macular degeneration, can help to save eyesight in some patients. Some researchers are working on treatments that use the spice saffron, that has been found to help protect against damage in the early stages of the disease.

Professor Kohn, who has submitted patent applications for “macular degeneration glasses”, started work on the condition when his wife Mara was diagnosed with the disease seven years ago, aged 80. Using computer algorithms he employs a square “Amsler Grid” – often used to diagnose macular degeneration – to assess a patient’s vision. Patients use a computer mouse to adjust the grid until they can see it perfectly, providing data that Prof Kohn and his colleagues can then use to manufacture a lens that corrects the patient’s vision.

The correction can also be applied to computer screens, allowing patients to read and use devices like mobile phones even without the glasses. He said he hopes to use thin layers of material to produce the same affect that could be used in contact lenses.

He also said that in the future he hoped to produce a small computer that could be worn behind a patient’s ear to alter the signal in the nerve from the back of their eye to correct any faults.

“Provided there is some vision in the eye, we should be able to correct the distortions,” he explained. “You would have a lot of information stored in a hearing aid like device and the information in the optic nerve could have the distortions removed.”

Sources:

1. Telegraph:
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