Most (natural) redheads will have brown eyes, followed by hazel or green shades. Blue eyes and ginger red hair is the rarest combination in the World!

Red hair is a distinctive physical trait that has been the subject of fascination and curiosity for centuries. People with red hair often have a unique set of physical features, including fair skin, freckles, and, of course, eye colour. But what is the most common eye colour for redheads? In this blog post, we’ll explore the science behind eye colour and investigate which eye colours are most commonly associated with red hair.

How eye colour is determined

First, let’s review how eye colour is determined. Eye colour is determined by the amount and type of pigment in the iris, which is the coloured part of the eye. The two types of pigment that contribute to eye colour are melanin and lipochrome. Melanin is responsible for producing darker shades of eye colour, such as brown and black, while lipochrome is responsible for producing lighter shades of eye colour, such as green and blue.

Ginger hair genetic mutation affects pigment in the iris as well as hair colour

But what about redheads in particular? People with red hair have a genetic mutation that affects the production of melanin, which is the pigment that gives hair its colour. People with red hair have lower levels of eumelanin (the pigment that produces brown or black hair) and higher levels of pheomelanin (the pigment that produces red or ginger hair). This genetic mutation can also affect the amount and type of pigment in the iris, which can result in a range of eye colours.

So, what is the most common eye colour for redheads? 

While there is no definitive answer to this question, research suggests that the most common eye colours for redheads are brown and hazel, as these are the most common eye colours in all hair types. Green shades are the next most likely eye colour, and finally the rarest colour of all for ginger redheads is thought to be blue and grey. 

How is eye colour determined?

Just as the MC1R gene determines your hair colour, a single gene, OCA2, is 75% responsible for your eye colour. For eye colour, the OCA2 gene determines how much melanin is in the iris, which is the coloured part of your eye, by controlling how much P protein is produced. People with blue eyes (a recessive trait), have very little P protein. This means you need to inherit two nonfunctional copies of OCA2 to have blue eyes. If you have at least one functional copy of OCA2, your eye colour will be on the spectrum of green-hazel brown, with two functional copies leading to a darker shade of eye colour.

In addition to OCA2, there’s another gene called HERC2 that controls how the OCA2 gene works. It does this by turning P protein production on and off. There are also eight additional genes that play at least a small role in eye colour, further adding to the genetic lottery of eye and hair colour.

Eye colours of the World, for all hair colours

Eye colour distribution varies around the World, with some countries having over 90% of their population with brown eyes. For Europe, Australia and the USA, these are the approximate percentages of eye colour: green eyes are the rarest, at around 9%, followed by approx 45% who have brown eyes and 27% who have blue eyes. So what about the remaining 19%? There’s a wide array of eye colours, ranging from violet, blue, grey through to hazel, green, brown, near-black. But they are all slightly different manifestations of green eyes, blue eyes or brown eyes. So while pale green eyes are rare, there are many people who have shades of green-brown eyes.

Conclusion

Most natural ginger redheads have brown eyes, followed by hazel or green shades. Blue eyes and ginger red hair is the rarest combination in the World!

See also this blog post for further information: Are red hair and blue eyes rare?