The number of children registered blind or partially sighted has risen as survival rates for severely premature babies improve, according to a charity.

New research has found a nine per cent rise in children registered blind or partially sighted, from 10,947 in 2006 to 11,928 last year.

Blind Children UK, which helps ­families tackle sight loss among their children, said there had been a 12 per cent rise over that period from 1622 to 1813 among under-fives.

It comes as overall survival rates among babies born between 22 and 25 weeks rose significantly from 40 per cent in 1995 to 53 per cent in 2006.

The earlier a child is born, the greater the risk of vision impairment, with one in 20 severely premature babies likely to be born blind, the charity said.

The charity said its survey of parents with children with sight loss showed they had reported feeling "depressed, isolated or upset" by the struggles they faced.

Parents said they had difficulties accessing playgrounds and events. There were instances of children being rejected from schools and nurseries as well as swimming lessons.

One-quarter said they had to wait longer than a year to have their child diagnosed with a vision impairment. Almost half felt this delay had a negative impact on their child's development as it meant they did not get the support needed from their local authority or school.

The charity, which collates data from public bodies across the UK, including the Scottish Government, said it was promoting advice for parents on how to spot early sight loss, a campaign supported by blind Paralympic gold medal winning swimmer Lord Holmes and the actress Joanna Page.

Lord Holmes said: "Every day four children in the UK are registered blind or partially sighted. Sight loss can leave children feeling isolated and afraid - I know this from personal experience."

The charity's chief executive Richard Leaman said: "Every day a child with sight loss goes without support, it dramatically affects their development. As much as 80% of a sighted child's learning takes place using vision."