Hereditary retinal dystrophies

As you may have already imagined, a totally blind person is one without functional vision. He or she may be able to perceive light, see shadows, colours, but that visual remain does not allow him or her, for example, to read a book, to see the blackboard, not even with optical aids.

Traditionally, the reading-writing system for blind people is Braille, although the technological advances make endless possibilities available to this group.