An experimental trial of gene therapy has helped four toddlers - born with one of the most severe forms of childhood blindness - gain "life-changing improvements" to their sight, according to doctors at Moorfields Eye Hospital in London.

A groundbreaking gene therapy has restored sight in four young children born with severe blindness due to a rare genetic deficiency. Scientists at UCL and Moorfields Eye Hospital successfully injected healthy copies of the defective gene into the retina,

Jace, 4, from Connecticut, was registered legally blind and only just able to distinguish between dark and light before undergoing treatment at Moorfields Eye Hospital in London

A young boy, by the name of Harvey, is seen before and after he received gene supplement therapy for a rare inherited eye disorder that caused him to be blind. The after results show a miraculous development in his eyesight.