since ive been watching a lot more tv i have been seeing double letters on a black background on the tv screen?

it all started when i got back into video games a couple of days ago and i could not stop playing them. i played the video games for around 10 hours a day with a couple breaks (including computer and tv) i would also stay up all night playing video games and i also have a bad eye from birth if this has anything to do with, my left eye is my bad eye and its always been blurry from birth because it didnt develope correctly, could it be that all the eye strain is going to my good eye and thats why im seeing double since my bad eye doesnt focus. when i noticed this i stopped playing video games for a day and only watched a little tv and noticed that it got a little better but i figured since it didnt get all the way better that i would just continue to play video games again. could this be eye strain? and i just saw my eye doctor today because of yearly anual check ups because of my bad and he said that my good eye is 20/20 and my bad eye is the same and i used to wear glasses but my doctor said it was no use and also after i got done with a video game i was outside with my brother and i saw his white shirt double in vision, not him or any thing else just his white shirt. so what it is and should i just give my eye a lot of rest? and thank you so much and sorry for the huge passage.ps i also sometimes get minor headaches