I recently learned Helen Keller played chess. I don't know the details, but I always assumed a set where one color is rough and one is smooth would work well. They would need to be very heavy to prevent knocking them over constantly. It sure would be hard to keep track of everything!
For casual play there are numerous solutions available to make a standard chessboard and pieces accessible to a blind or visually impaired players. A solution that comes to mind is glue dots. They are small tacky spheres that can be stuck on and later removed. They can be placed on top of chess pieces to make black and white identifiable. They can also be stuck to the board. By placing say a glue dot on each corner of the black squares then diagonals would be identifiable by corners of neighbouring black squares. The two glue dots would be perpendicular to the diagonals of the white squares. Of course this would mean no sliding of pieces but that is a small concession.
On a tournament sized board there would be space outside the playing area to create Braille indices using the glue dots too.
(The Glue Dot idea is just a suggestion).
I agree that especially in the early stages, weighted wide based pieces would definitely help.
I have met blind and visually impaired people who operate and live in environments designed for the sighted. I confess to have forgotten from time to time they were blind. If they can use a cooker, make cups of tea and such without knocking stuff over then I am sure that with some practice they will learn the scale of the board and have an expectation of where the pieces will be to be able to not perpetually knock them over.
If knocking pieces off their squares thus causing confusion continues to be an issue then aside boards designed for the blind, there is the Umbra Wobble Chess Set that could go some way to solving this problem. Umbra Wobble set from Amazon UK
At the end of the day it is all about what the Blind/Visually Impaired person wants and they might not want something that makes it obvious to onlookers that they are blind.
I recently learned Helen Keller played chess. I don't know the details, but I always assumed a set where one color is rough and one is smooth would work well. They would need to be very heavy to prevent knocking them over constantly. It sure would be hard to keep track of everything!