I don't know about the problem with colors, but the trouble you're having with focusing on letters/numbers, etc. sounds to me like you're starting to experience simple presbyopia, which frequently starts in the late 30's (it did for me) and early 40's. That may be an oversimplification, and I'm not sure how your back pain relates, if at all. However, presbyopia simply comes with age and is easily treated with progressive eyglasses or bifocals. Just a thought. Good luck, and please tell us how everything turns out.
Do you have anything constructive that you an actually help by saying please?
It took me 4 hours to be able o write that post, how long did you read it for.
perhaps if you had taken the time to actually read what I wrote you would have seen I already have had a baseline exam.
You need a baseline eye exam by an Eye MD ophthalmologist.
JCH MD