I can't see or read out of my new glasses?

I just got new glasses, same power as my old ones and I can't read or barely see out of them. I see and read better without them on. What is the deal? My powers haven't changed according to my doctor, so why are these glasses worst then my old ones? My old ones were plastic lenses and my new ones are the Nikon lenses. I'm only 18 years old.

Added (1). My powers in both eyes are -4.50

What's the prescription?

Take them back. Sometimes mistakes are made when lenses are produced.

If the old and new glasses are the same prescription, you should see the same through both of them. Take the new ones to your doctor and ask them to check them. They have an instrument that can do this.

Someone made a mistake. It could have been the doctor or staff sending the prescription to the lab or a lab error. Nikon is a brand name. Virtually all glasses made today have plastic lenses.

Somebody goofed… A common occurance for some places.

The brand of lenses really have nothing to do with it. In single vision lenses they are all the same thing.

How come you didn't notice that or say anything when you picked them at at the store?