Board Vision

Not "board vision" in terms of seeing things while analysing the position in your head, but real, how well you see the board with your own two eyes, vision.
This who played in Blayney on the weekend (or Dubbo, Taree previously) would be familiar with Alex Momot. For those who aren't, Alex is a regular weekend chess player, who also happens to be blind. When he plays he uses an extra board where he can feel the location of pieces with his fingers, and announces his moves to his opponent. Seeing him play made me wonder what affect vision has on playing strength, and today I received a partial answer.
Gus Korda has been playing Street Chess in Canberra ever since it started (about 18 years ago), although he has been struggling with eyesight problems for the last couple of years. This has coincided with a drop in strength, although age might have been a factor. Nonetheless he had some treatment for this problem over the last couple of weeks, and clearly something has worked. Returning after a weeks break he started the event with 5/6 (losing only to perennial winner Endre Ambrus) before Emma Guo joined him second place after defeating him in the final round. He confessed that not being able to see much of the board has affected his results, but having 2 working eyes does make a difference.