When it comes to the pilot sunglasses frame, a frame should be better consists of rims to hold the lenses, supported by a nosepiece, and attached by hinges to temples which secure the system to the ears. Because of vibration, any screws used in frame construction (rim closure, temple attachments, and nose pads) should be locking.In general, frames should permit good peripheral vision, be comfortable, securely fitting, robust enough to take rough handling, and be compatible with headgear. Rim size and shape should be optimised to the orbital contour of the wearer. In some makes of sunglass, the lens is not held particularly securely into the frames. Pilots should choose sunglasses with deep rim safety bevels to securely hold the filters so that these cannot dislodge in flight.Temples also come in various cross sections. Due to pressure under headphones, a flat profile is recommended for pilots, who should take their headsets with them when trying on any new glasses.