What makes our eyes change color?

Question

Sometimes they are dark green, sometimes they are light green, when I was young they were light brown.

I know about Mendel, so I am not asking about genetics. I understand pigmentation and melanine. What I want to know is what substances or chemicals cause the infinite variations in eye color shades we see around us all the time.

No doctor has ever been able to tell me, can one of you?

Answer 1

Your eye colour is defined by the amount of melanin you have in your iris. Melanin is the brownish pigment also found in your skin which defines skin tone. Paler people have less melanin, while people with darker skin have more. Equivalently, a lower number of melanin in one's iris makes the iris blue. More melanin makes the iris green, and the colour with the most melanin is brown.

There are certain drugs such as Latanoprost which have been found to darken the eyes. Heterochromia-- two different coloured eyes, most frequently shows up during one's lifetime, but can also be caused by certain drugs. Others claim that diet can change one's eye colour, though there hasn't been any solid scientific evidence to support this. Sun exposure has been pointed out as a possible explanation for change in eye colour as well.

Apart from physical factors, there are also human interpretations of eye colour. Depending on the lighting, the colour surrounding the person, and any other factors that could alter the brightness/darkness of the eye colour, a person's iris may appear to 'change'. Though there are technically only three eye colours--brown, blue, and green, there are many variations humans have created (hazel, grey, amber, black, etc.)

There's more information below in the links I've pasted.

Answer 2

The change in eye color is caused by an increase or decrease in melanin the stuff that makes your eyes more or less colorfull. Brown eyes contain the most melanin then hazel next blue and last green and yellow. Also it can have do do with pigmentation issues or even when you have a tramatic injury it may cause your eyes to change color because of a loss in pigmentation.

Answer 3

There is some answer as to why they change as we age, but I don't know. It's the same reason most babies are born with blue or brown eyes, which can change.

As to dark green v. light green, your eyes are not technically changing color. The lighting you're in, and the colors around you (such as your clothing) can affect the color your eyes appear. I call this chameleon eyes; I have them as well. When I wear dark colors or in bright light, my eyes look hazel. When I wear bright colors, they look muddy. When I wear pale colors, they look green. It's not actually a change in pigment.

Answer 4

My sister's eyes change color. Most of the time they are sort of hazel, but when she is upset they turn bright green. WHen she is upset enough to cry, her eyes turn red in the "white" area and bright green in the iris, and the color contrast red/green makes the color change even more striking.

I think it's sometihng like the way amphibians can change the color of their skin, by dilating or contracting pores in their skin that are different colors. Perhaps in some people there are different layers of tissue in the iris that have different colors, and when the person is stressed or relaxed this may cause the muscles of the iris to dilate or contract and show different colors.

Answer 5

It's an enzyme (protein) that's present in your body that directs the color of the eye...

If that's not present then, I don't think there would be any change in the eye color... (It would basically stay the same from birth)

Hope this helps...

Answer 6

No, and I'm a paramedic with over 25 years experience. I also have a wierd eye color. Mine are very light brown with dark brown edges or I call it "borders".

Answer 7

Drinking?