Scientists have successfully erased drug-associated memories in mice and rats without affecting any other recollections, according to a study published in the journal Biological Psychiatry. The findings point to a clear method through which memories can be disrupted, even as all others remain carefully intact, according to the researchers. (Photo : Wikimedia Commons/ George Shuklin (talk))

Researchers from Oxford University have restored the eyesight of blind mice by injecting light-sensing cells into their eyes.

For the study, the research team examined mice that lacked photoreceptor cells in their retinas. Photoreceptor cells are specialized neuron cells that detect light and enable one to see.

The mice involved in the study were not able to differentiate between light and darkness.

The team injected the blind mice with precursor cells that develop into building blocks of retina inside the eyes. After two weeks, experts noticed that a retina had formed in the eyes, reported BBC.

They tested the mice to see if they responded to light and also scanned their brain to check if the visual data was transmitted to the brain, after the entire light-sensitive layer was restructured.

"We have recreated the whole structure, basically it's the first proof that you can take a completely blind mouse, put the cells in and reconstruct the entire light-sensitive layer," Prof. Robert MacLaren, from the Oxford University, told BBC.

The loss of photoreceptors causes blindness even in humans. Experts hope the study will help in treating degenerative eye diseases in humans.

The findings of the study appear in the journal Proceedings of the National Academy of Sciences.

In a similar study in April 2012, Robin Ali from the UCL Institute of Ophthalmology in London and his research team showed for the first time that transplantation of photoreceptors could restore the vision of visually impaired mice.

The study, published in the journal Nature, explained how injecting cells from healthy mice into eyes of adult mice that lacked rod-photoreceptors could help restore their vision.

Rod cells are important to see in dark environments. The study also suggested that the transplantation method could be used as a basis for new treatments to help restore the vision of people with degenerative eye diseases.