The frame of these enhanced goggles is made from extremely tough, durable polyurethane. It is highly resistant to shock, low temperatures and scratching, and so offers ample protection for the delicate electronics contained within. These include the infrared light emitter and head-up display, which combine to give the goggles night-vision capability of up to twenty metres, even on a moonless night. The light-emitting diode concealed in the frame puts out an impressive 150 milliwatts of infrared light, which is comparable to military-issue infrared torches. It is useful for enhancing infrared vision in low temperature conditions. In order to avoid giving away the night-vision capability, this does not work in the same way as commonly available infrared goggles, in which the wearer looks through two eyepieces at miniature video screens. Here, a pair of concealed lowpower lasers on the inside of the frame is used to project the infrared image data directly onto the lenses. The lenses themselves are a many-layered “sandwich” of different materials. The protective coatings on the outer layer prevent scratching, fogging and icing, and cut down on glare and UV rays for improved visibility and safety in almost all light conditions. The inner layer is coated with a material that glows in laser light, to facilitate the head-up display. Layers of polycarbonate laminate in between give a good deal of resistance to bullets, although this should only be relied upon as a last resort. The built-in rechargeable battery made of lanthanum, nickel and tin is a great improvement on previous designs, including those commonly used in mobile phones and laptop computers. It holds a charge for much longer, and battery life does not decrease as much with each recharge. Solar panels built into the frame continually trickle-charge the battery when the goggles are exposed to light.