Seiichi Miyake is the inventor of the tactile, or Tenji blocks, which are used in public spaces like sidewalks and train and subway platforms to help those with visual impairments.

According to the Doodle, Miyake had a visually impaired friend, who was beginning to struggle to get around. Miyake used his own money to create the Tenji blocks, which typically feature either dots or bars similar to the tops of Legos, to alert his friend to what lay ahead. The raised dots on the Tenji blocks signify approaching danger, such as at the edge of a sidewalk. Raised bars are used as a directional tool, and let the user know they are still on a safe path.

Miyake invented the Tenji blocks in 1965, and they were first introduced on a street near the Okayama School for the Blind in Okayama City, Japan, on March 18, 1967. They were quickly implemented across Japan and were made mandatory in the country’s train stations. Other countries, such as the U.S. and Canada, followed suit in the ‘90s.

Tenji blocks, also known as “braille blocks,” can be felt through the user’s shoes. Those who use a cane can also feel the raised dots and bars that way, or guide dogs can be trained to read them. While Tenji blocks are perhaps best recognized in their signature yellow color, the blocks can be found in other colors as well.