Talk to Eye Specialist on My Eyes Hurts And Waters After Reading Or Watching 5 Minutes

so recently i've been reading alot (mostly books and articles ect) and i've started to realise that after about 5 minutes of reading anything my eyes start to hurt/ache, and if i keep reading for 10-30 minutes more they can hurt to the point where i have a headache and or feel sick from it, this has also hindered my ability to concentrate on what im reading, some times i feel focus problem, i often find myself unsure of what is happening, my vision was perfectly fine and has been in the past, any ideas as to what could be the problem?