What are the signs of going blind?

I've worn glasses since i was 5 now that i'm 17 i tend to wear them on and off so not always but recently i've noticed my vision gets blurry/water with or with out it goes when i blink sometimes it recurres but then i blink and it goes its a bit like when you wake up in the morning and your eyes are watery but then it goes when you blink. Am i going blind? pls answer asap i'm really worried