Google, with their usual innovative zeal, have come up with a novel design for a low-cost virtual reality viewer that enables you to turn a sheet of cardboard, some magnets, a rubber band and a couple of simple lenses into a VR headset that uses your smartphone as a screen (see developers.google.com/cardboard). This is great, but where to get those lenses from? Comar stock premium quality 40mm focal length biconvex lenses on our online optics site - click here! These instrument quality crown glass lenses are precision finished and will give a clear, undistorted image. They are easily cleaned with a soft tissue and are highly resistant to scratching.