i've been meditating for eight years. my method is sitting upright with my eyes mostly open but relaxed and gently focused on whatever is in front of me within about four feet, usually the floor or a coffee table. i sit and focus on my breathing. two or three times i have meditated for thirty minutes and after have experienced blurred vision when trying to read anything. this lasts about twenty minutes and then returns to normal.
the first time this happened i had been meditating outside and had been looking at something about thirty feet away so i thought maybe it had something to do with the way my eyes were focused so i started fixing my gaze on something closer and a year went by without incident until today i had the problem again.
has this happened to anyone else? is there a way to prevent it?

