London, March 6 (IANS): Ever wondered how we can see sharp images though a blur is projected in each retina?

This is because when each eye separately has a different level of blur, our brain uses as sharp reference the image projected through the eye with the lesser aberration, reveals new research.

In this way, the brain works like a Cyclop - the mythical one-eyed creature.

The finding could help to improve the treatment for presbyopia.

"Our impression about what is sharp is colossal and it is determined by the sharper image among those which are projected through both eyes," said Spanish National Research Council (CSIC) researcher Susana Marcos.

The research reveals that despite these blur differences, the perception of each eye separately about the sharper image is the same, regardless of the eye we use to make the test and coincides with the blur image projected through the eye with the lesser aberration.

The nature of these visual calibrations is important in order to understand the different consequences referred to the refractive errors between both eyes.

"For instance, an available solution to correct the presbyopia is monovision, in which different refractive corrections are provided for both eyes."

"One eye, the dominant eye, is corrected for distance viewing and the other one is corrected for vision viewing...the main objective is to provide the best possible correction," said Marcos.

The research has been published in Current Biology.