Can i use reading glasses without having side effects?

Sure: Although looking through the wrong "strength" reading glasses can cause eye strain, it cannot cause permanent side effects. This is one of the reasons that readers are available without prescriptions. Some people feel more comfortable using reading glasses even if they are not necessary. The only possible side effect would be headache from using either too week or too strong glasses.

Yes: The only side effect is diminished reading ability when you do not wear necessary reading eyeglasses.