Hannah and Katie Beck are the only twins in Britain who are suffering from a rare genetic disorder that affects just 800 people worldwide.
The seven-year old twins suffer from a condition known as Alstrom syndrome, which is so rare that doctors failed to diagnose it until the sisters were four years old. The condition affects all organs of the body and one of the first symptoms being eye problems, which leads to early-onset blindness.
The twins are also slowly losing their hearing and have to wear dark glasses all day as their eyes are very sensitive to light. They are also being trained to walk using white canes and read through Braille.
Their parents, Julie and Ian, both carry Alstrom syndrome gene but are unaffected, said that they want to help their daughters enjoy life before they completely lose their sight. "We've been trying to do things while the girls can still see them. We took them on their first holiday abroad to Lanzarote in February and Hannah particularly loved it and begged to go back again so we're going back next year. Katie is just into princesses, she loves all the Disney princesses, so we want to take them to Disneyland", Julie said.