Researchers at the University of Nottingham said the discovery could improve outcomes for patients undergoing corneal grafts and transplants.
The new layer has been dubbed the Dua's Layer after Professor Harminder Dua, who discovered it, a university release said Tuesday.
"This is a major discovery that will mean that ophthalmology textbooks will literally need to be rewritten," Dua said. "Having identified this new and distinct layer deep in the tissue of the cornea, we can now exploit its presence to make operations much safer and simpler for patients."
The human cornea, the clear protective lens on the front of the eye, had been believed to be comprised of five layers: from front to back, the corneal epithelium, Bowman's layer, the corneal stroma, Descemet's membrane and the corneal endothelium.
The new layer, located at the back of the cornea between the corneal stroma and Descemet's membrane, is just 15 microns thick but is incredibly tough and is strong enough to be able to withstand considerable pressure in the eye, the researchers said.
Understanding the properties and location of the new Dua's layer could help in the understanding of a number of diseases of the cornea, they said.