“This means there’s a more even scattering of all the lights that’s not frequency-dependant,” he adds. This is similar to a grey, cloudy sky, because when light hits the water droplets, all the wavelengths are scattered equally. Except, instead of water droplets, there are collagen deposits.
Article source: https://www.huffingtonpost.co.uk/entry/grey-eyes-meaning-tiktok-doctor_uk_6a3a83f9e4b058c5d1c43724