The lenses are made of plastic. not of highest quality to say the least It has some optical distortion right in the middle of the field - could be annoying at times. The lens holder is a bit loose so the lens moves while tilting my head. I had to improvise so it holds better. The unit holds well on the head, with good independent adjustments for the size and the height. The working distance is SHORT (picture taken from the product leaflet). This is what you get for <$20...
The lenses are made of plastic. not of highest quality to say the least It has some optical distortion right in the middle of the field - could be annoying at times. The lens holder is a bit loose so the lens moves while tilting my head. I had to improvise so it holds better. The unit holds well on the head, with good independent adjustments for the size and the height. The working distance is SHORT (picture taken from the product leaflet). This is what you get for <$20...