An eye implant that's smaller than a grain of sand has the potential to revolutionise the treatment of glaucoma, which is a leading cause of blindness. 

The implant measures just 0.2mm by 1mm and is a tiny polyester plug that gradually releases bimatoprost.

This is a drug that's already found in eye drops that are often prescribed to patients to treat glaucoma. 

With more than seven in ten patients failing to use the drops properly, this highly reduces the benefit of the drug and others suffer from side-effects of the eye drops.

It is hoped that the implant will improve treatment as well as slow down the progression of the disease.

Glaucoma is most common in people in their 70s and 80s and is often caused by fluid building up in the front part of the eye.

This increases pressure in the eye and squeezes the optic nerve, killing some of the fibres needed to transmit information to the brain and leads to a loss of vision.

The implant's benefits last for around eight months, with a patient only being able to be fitted for one.

It is hoped in the future that they are able to have replacements when needed.

"Anything that makes it easier for people to manage glaucoma is a good thing," says Daniel Hardiman-McCartney, clinical adviser for the College of Optometrists.

"Implants are a possible option, but recent research suggests that a pressure-lowering laser treatment called selective laser trabeculoplasty may be even more helpful."