We’ve written before at HuffPost UK about how people with grey eyes are that colour for the same scientific reason a cloudy sky is grey.

And now it seems there’s news for fellow green-eyed people; there’s more going on in our irises than you’d think, doctor Karan Rajan says.

The doctor, who’s known for spreading his medical knowledge on TikTok, started his clip by saying “If you have green eyes, you actually have three eye colours that blend together.”

I know ― I was taken aback too.

But the doctor explains that the eye colour works a bit like paint pigments ― it combines a mixture of different shades to create a uniform effect.

Firstly, green eyes have a little bit of a yellow pigment called lipochrome. “This is found in stroma of the iris,” Dr. Rajan explains.

Those with green eyes also have a small amount of brown pigment in the same area ― this is melanin.

You’ve also got a bit of blue in your eyes if your irises are green, Dr. Raj shared in his video.

For those of us with jade-coloured peepers, “even though the iris has small amounts of melanin, it’s such a small amount that most of the light is scattered and reflected back” as blue.

The combination of these layers creates a green effect, the doctor finishes.

Not to that extent. Deep brown eyes are that way due mostly to melanin, while true blue eyes have very little.

However, “while there are just a few main colours, the ways those colours can show up are infinitely complex,” the Cleveland Clinic says.

For instance, hazel eyes are a combination of brown, gold, and green.

Still, according to the Cleveland Clinic, “Not counting colours like red/pink from conditions like albinism, the rarest of the main eye colours is green.”

They add that “about 2% of people worldwide have green eyes.”