Today, Google's daily Doodle celebrates the work of Japanese inventor Seiichi Miyake. See above screenshot. (I wonder who at Google is responsible for coming up with these. Imagine having to post something new every day.)

I am sure that most of you have come across these tactile paving blocks before in the subway or in some other public space. But I for one wasn't familiar with their origin.

Invented by Seiichi Miyake on his own dime after a close friend started becoming visually impaired, they were first introduced in 1967 on a street in Okayama City (Japan) next to a school for the blind.

Since then, these tactile blocks -- or Tenji blocks -- have been adopted all around the world as a way to help the visually impaired navigate our cities and public spaces.

There are two main types of blocks: ones with bars and ones with dots (which are kind of like domes with their tops cut off). The bars indicate a safe path of travel. And the dots tell you when to stop (such as at the edge of a subway platform).

The idea is that these different kinds of blocks can be detected with either a cane or through your feet as you walk over them. It's a pretty simple idea, but it clearly seems to work.

All of this reminds me of a recent community meeting I was at where I heard a lady -- who was visually impaired -- speak eloquently about the importance of thoughtful materiality in our public spaces. I think she may have been an architect or designer.

One of her comments was that echoey spaces can be overwhelming for people with limited vision. That makes perfect sense to me. Unfortunately, I think it can be hard to fully appreciate some of these design subtleties unless you're living it.

But as Seiichi demonstrated, maybe all you need is a close friend who is living it.