We need light to see. That much we all know. The thing is, not all light is the same to the human eye. There’s light the eye can use, and there’s light that makes it hard for the eye to do its job. When sunlight reflects off horizontal surfaces like tarmac, water, pavement or even grass, much of it is concentrated in horizontal waves. This horizontally polarized light is seen as annoying glare.
This glare masks useful light which is travelling in the vertical direction. The result is, you can’t see properly, and you tend to squint or just close your eyes. And you don’t even need a sunny day. You can get glare on overcast days because light still reflects off horizontal surfaces and becomes concentrated in the horizontal direction. Polarized sunglasses have a special polarizing filter in the lens that blocks horizontally reflected glare and lets in vertically travelling light that the eye can use. A lot of science goes into polarized sunglasses, but what you notice is that compared to ordinary sunglasses things just look clearer. And, your eyes will be more comfortable.
Polarization was invented in 1932 by Mr Edwin Land. Soon after that he established the Land-Wheelwright Laboratories to give his invention commercial scope. The company was renamed the Polaroid Corporation in 1937. A host of innovations followed. In 1947, Land launched the first instant camera and continued with the development of instant colour photography in the 1970s, the year Polaroid Eyewear became part of the specialist eyewear company, StyleMark. Until he left the Polaroid Corporation in the 1980s, Land continued to be a force for innovation. He employed women and trained them as research scientists, and the company was known for its support of racial equality long before such things were expected.
The technology has been widely used and refined down the years, and is now used in a multitude of areas including vision, but especially within the eyewear field, with everyone from Polaroid themselves to Chanel, Gucci and Oakley glasses utilising it. So, as well as inventing something that helps us see clearer, he was a pioneer in many different ways. Here’s to Edwin!