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| Light dispersion |
In dark eyes, the iris contains pigment granules, while blue eyes and the eyes of albinos lack pigment.
So, Blue eyes don't contain any blue pigment at all and the colour that we see is actually caused by the Tyndall effect, which is similar to the Rayleigh effect, which makes the sky look blue.
In our eye, longer wavelengths of light tend to be absorbed by the dark underlying epithelium, while shorter wavelengths are reflected and undergo Tyndall scattering in the stroma, which is the upper layer of two in the iris. People with blue eyes have a completely colourless stroma and no excess collagen deposits. This means that all the light that enters the stroma it is scattered back into the atmosphere, resulting in a blue eye colour.
Research shows that people with blue eyes are all related to a single, common ancestor, who lived 6,000-10,000 years ago when a genetic mutation took place.
Also, there are no blue birds. Blue-coloured birds such as the blue-and-yellow macaw, appear blue because nanochannel structures on the feathers of birds, alter their light-reflective properties and scatter light strongly at specific frequencies. Some birds also get their colour from pigments in the foods they eat. Which means that the colour of flamingoes comes from eating prawns (shrimps).
“Why is the sky blue?”. When light hits the particles of nitrogen and oxygen in our atmosphere, it scatters in all directions. Blue light has a smaller wavelength than red light, so it scatters to a greater extent than red light. So, It is this scattered light that gives the surrounding sky its brightness and its colour.
So, Blue eyes don't contain any blue pigment at all and the colour that we see is actually caused by the Tyndall effect, which is similar to the Rayleigh effect, which makes the sky look blue.
In our eye, longer wavelengths of light tend to be absorbed by the dark underlying epithelium, while shorter wavelengths are reflected and undergo Tyndall scattering in the stroma, which is the upper layer of two in the iris. People with blue eyes have a completely colourless stroma and no excess collagen deposits. This means that all the light that enters the stroma it is scattered back into the atmosphere, resulting in a blue eye colour.
Research shows that people with blue eyes are all related to a single, common ancestor, who lived 6,000-10,000 years ago when a genetic mutation took place.
Also, there are no blue birds. Blue-coloured birds such as the blue-and-yellow macaw, appear blue because nanochannel structures on the feathers of birds, alter their light-reflective properties and scatter light strongly at specific frequencies. Some birds also get their colour from pigments in the foods they eat. Which means that the colour of flamingoes comes from eating prawns (shrimps). “Why is the sky blue?”. When light hits the particles of nitrogen and oxygen in our atmosphere, it scatters in all directions. Blue light has a smaller wavelength than red light, so it scatters to a greater extent than red light. So, It is this scattered light that gives the surrounding sky its brightness and its colour.
“Why are sunsets red?” When the Sun appears lower in the sky, the light that reaches us has already travelled through a lot more of the atmosphere, as sunlight travels a long way through the atmosphere to reach our eyes, which means that much of the blue has scattered out long before the light reaches us, so the sky appears redder.
Clouds appear white because the water droplets are much larger than the wavelengths of light and so all wavelengths of light are equally scattered in all directions.
Clouds appear white because the water droplets are much larger than the wavelengths of light and so all wavelengths of light are equally scattered in all directions.
