Leo Lake, a five-year-boy from Hove, UK has a rare condition known as Joubert syndrome which makes his eyes sensitive to light. Even the reflective glare of the sun off snow can leave him in agony.
He must wear sunglasses all the time because daylight robs him of his sight because bright light irritates his eyes so much that he can't see anything at all.
With the sunglasses, he can see a metre in front of him, which his mother Hannah says is more than she could have ever hoped for.
The 27-year-old said: 'Without his glasses, he can't see in bright lights and sunlight, it's excruciatingly painful for him, he just screams and cries.
Leo was born in South Africa after his grandmother moved there to fulfil her dream of owning a guest house.
'When he was five weeks old, I realised that when I spoke to him he would smile but in the wrong direction,' said Hannah Lake.
'I took him to the doctors because I knew something was wrong, but they kept telling me he was fine and they couldn't tell whether he could see or not. It was very frustrating.
'Eventually after numerous tests they told me he could be blind and I was just devastated.
'I'd never had any contact with blind people before and I was worried I wouldn't be able to give him the care he needed.
'But at the same time, a part of me still believed he wasn't blind, I was sure he had vision.'
Hannah moved back to the UK when Leo was 10 months old because she believed he could receive better healthcare. She said: 'When we first moved back Leo seemed a lot happier, I missed the sunshine, but was much better. So we had numerous tests, but nothing was being diagnosed.
'It was at the age of two when he still wasn't walking that I became really concerned.'
When Leo was three years old he was finally diagnosed at Moorfields Eye Hospital with Joubert syndrome.
The syndrome is a rare genetic condition with which the cerebellum, part of the brain that controls balance and co-ordination, is underdeveloped.
Symptoms include poor sight and problems with movement as well as sensitivity to sunlight and bright lights.
Currently there is no cure, but Hannah set up her own foundation, VisKid, last year with the hope of raising enough money to one day cure Leo's condition.
So far she has managed to raise £1,500, but £250,000 is needed to fund the three-year research into what is a realistic cure.
Ms Lake said: 'Leo knows he's different to other children, but he still doesn't fully understand his condition.
'He's very popular with the other kids, they love him, so luckily his glasses haven't caused too much of a stir at school.
'People ask him why he wears sunglasses all the time, I tell him to say they're his magic glasses to help him see.
'Luckily he thinks his shades are cool.'
Leo is registered blind and has ataxia and kidney cysts that will eventually lead to kidney failure.
Hannah said: 'Apart from not being able to play sports properly because of his balance, Leo's just a typical boy, he loves cars, trucks and trains.
- DM
0