Is it worth telling my examiners about my eye problem?

I have this "induced nearsightedness" thing with my eyes where my vision gets blurry after staring at something that's nearby for a prolonged amout of time without taking time to look at something else further away. When I finally look away at an object further away, my vision becomes very blurry and could last from 30 seconds all the way to 5 minutes, depending on how long I was focused on the nearby object. This is a big problem if I'm sitting an exam because I'm spending roughly 2 hours, more for some, looking at my paper which is right infront of me, and at the end of the exam once I look up everything is blurry and I can barely read the time on the board, it's quite scary. It does always eventually come back into focus, but it does get very blurry for a short while and I'm worried that at some point it might stop going back to normal and make me permanently nearsighted. Should I tell my examiners if I could maybe get extra time / breaks to rest my eyes, or maybe write my paper on a computer further away or something like that, or is it not really that big of a problem?