Complex sentence: Tactile electronic displays (aka "refreshable Braille display") are usually intended for the blind or visually impaired, they use electro-mechanical parts to dynamically update a tactile image (usually of text) so that the image may be felt by the fingers.
Split into simpler sentences: Tactile electronic displays (aka "refreshable Braille display") are usually intended for the blind. They use electro-mechanical parts to dynamically update a tactile image (usually of text) so that the image may be felt by the fingers.