Eyestrain - Anyone experiencing eyestrain when playing OTB? As the title says. When playing blitz (3 to 5-minute games), I experience eyestrain after 10 or more games. After that, I start to blunder. I get tired too fast.

In our area, it seems to be only me who has this issue because my opponents can play a whole day without signs of exhaustion. Their plays don't change while my play changes after few blitz games. It is like starting from Elo 1850 then after few games it seems that I am playing like in Elo 1500-1600 while my opponent's strength and any other players' strengths in our area are the same the whole day.

Btw, I work online for at least 10 hours each day Monday to Friday. I play only on weekends. I have computer eyestrain too (a different case, not OTB chess eyestrain). But on weekends I still get eyestrain even when playing OTB only and not using a computer. I get enough sleep on Saturday, so I should not get eyestrain on Sunday when playing OTB, but it still happens.

If anyone here experiences the same issue, I would appreciate your suggestions on how to solve this issue.

Thanks for your ideas.
If you are genuinely getting tired "after 10 or more games" because of eyestrain and not just because you are getting old or you play in a stuffy, crowded room where there isn't enough oxygen then I would suggest you have a problem with the lighting. 

In some playing areas I have problems when there is not enough light (maybe I'm in a darker corner of the room) or there is not enough contrast between the colours on the board and / or the colours of the pieces. This can give me eyestrain and make me feel tired but it would happen to me much quicker than after 10 games of blitz. If anything for me it would get a bit better after a while as my eyes and brain adjust a bit to the bad lighting conditions.

Note that some people have a problem the other way with over bright fluorescent lighting so I guess for tournament organizers it can be tricky to get it just right.

If I were you I would try and work out which lighting conditions give you the most problems and either sit somewhere where these problems are minimized and maybe if necessary ask the tournament organizer for help on this.