（76）For more than 60 years，Lego（乐高）bricks have sparked children's imaginations. Now，a new version of these toys is in the works. They're Lego Braille Bricks,and they're being tested around the world. Lego Braille Bricks are designed to help people learn Braille. That's a system of writing in which letters are represented by raised dots. People who are blind or visually impaired（弱视的）use their fingertips to read. According to the World Health Organization,36 million people worldwide are blind.In the United States,it's estimated that only 10% of blind children learn Braille.Lego Braille Bricks can help change that. The small knobs on the bricks are arranged as Braille letters. Blind children can use these knobs to learn Braille. Lego plans to launch Braille Bricks next year.(77)For some schools and institutions,they will be free.Each set will contain about 250bricks. Along with the alphabet, the bricks will feature numbers and math symbols. The Danish association of the Blind was the first organization to come up with the idea of using Lego bricks to teach Braille.Thorkild Olesen is the president of the group. Olesen is blind. He says many teachers don't have the tools and skills to help kids learn Braille.So they teach with audio（声音的）tools，such as audio books.“Like any other people，we need to express ourselves in writing. Audio can never replace Braille. Braille is the single most important tool for us to learn to spell correctly and write like sighted people." “This is particularly critical when we know that Braille users often are more independent, have a higher level of education and better employment opportunities. We strongly believe,”Olesen continues,"Lego Braille Bricks can help promote the level of interest in learning Braille.”