Just for fun, let's look backwards to the first head worn lamps.
Calcium Carbide Miners Lamps were state of the art because they provided a fairly bright (for 1900) light using acetylene gas.
Here are some pictures of how far we have come....

- Calcium Carbide Lamp Drawing.PNG (380.45 KiB) Viewed 757 times

- Head Lamp Circa 1920.jpg (23.66 KiB) Viewed 757 times