Shine a small light onto the lense from directly above, and look at the lense from an angle. Flip the lense over and figure out which side has less glare on it. Also, it might be coated on both sides.
Most AR coated lens will have an uncoated ring of exposed glass on the coated side. This would be from the fixture used to hold the lens in the vacuum evaporation chamber. You should be able to see it when you wiggle the lens under a light while looking at it at an angle. Also, the reflection should have a hue of color in the reflection as well.