incorrect eye prescription

My son was complaining that he could not see the words written on the black board in school, so i took him to the doctor and he gave him an eye prescription of +1.50 for both eyes with axis 90 and said that it was for distance and not for nearsightedness.  My son started wearing those eye glasses with the prescription recommended by the doctor.  My son told me that everything on the board looked strangely big, bigger than normal. I am guessing that maybe the prescription is wrong.  My question is isn't the prescription for distance is in the negatives for instance shouldn't it be -1.50 instead of +1.50 maybe that is why my son is complaining about the words being too big, much bigger than normal.  Please tell me what maybe wrong with this prescription or maybe everything is fine and it is supposed to be this way.  

[Ray T Oyakawa, MD]

You need to take him back to get the glasses and prescription checked.  It should be a no charge visit.  Distance prescription can be + or -.

Dr. O.