Distance glasses for myopia (prescription, sight, itch, normal)

[timlee]

I am near-sighted (-3~-3.25 for Sph for right and left eyes, and -0.5~-0.75 cyl).
I have a pair of glasses made based on that prescription.

1. I think the glasses are only meant for seeing distant objects, instead of close ones, such as reading a book or computer. But in a classroom, how can I switch from looing at the blackboard with a pair of distantce glasses, and reading mylaptop screen or books? Do I read both distant and close objects using the minus glasses?

2. Whenever in a day when I have to wear my glasses, I found that after I take off the glasses, my vision will become, even worse than it was before putting the glasses on. So I was wondering if that is normal? How would you gain your naked vision back as quickly as possible, after wearing the glasses?

Thanks!