Most people when they look at a clear blue sky, they see a yellow bow tie-like pattern or propellor-like pattern. It’s called Haidinger’s Brush. It’s based on our ability to perceive polarisation of light. I noticed this as a child when I was growing
up in India but only later learned the significance of it. My sari here has the pattern of Haidinger’s Brush on it. The ability to see this brush-like pattern has been the basis for the test that’s regularly used in the clinic to tests for macular degeneration, or squint or lazy eye for example. Our device which involves projecting Haidinger’s Brush onto a screen can be used as a simple test for shop windows. These tests can be incorporated into a portable device for optometrists and if you look at the centre of the device and see a very different pattern centred on the dot, then you’re fine, otherwise you need to consult an optometrist. Just look onto the small black dot, what sort of pattern can you see? I see a propellor spinning around on the centre of the dot. That’s good, you’ve passed the test. This test can even be used in the cinemas
where people are waiting for the movie to start. The best thing about our innovation is that we’re able to bring the test free of cost
to the masses in one go.