MIT develops new incandescent light bulb that is cheaper than LEDs

From the UK Telegraph:

Researchers at MIT have shown that by surrounding the filament [in the traditional incandescent bulb] with a special crystal structure in the glass they can bounce back the energy which is usually lost in heat, while still allowing the light through. . . . 

Usually traditional light bulbs are only about five per cent efficient, with 95 per cent of the energy being lost to the atmosphere. In comparison LED or florescent bulbs manage around 14 per cent efficiency. But the scientists believe that the new bulb could reach efficiency levels of 40 per cent. . . . 

But if the new bulbs live up to expectations they would cost under 50p a year to run and even improve health. . . .