While this question is very subjective, there is some science to one aspect of it:
Blue eyed men have been scientifically proven to prefer blue eyed women. This due to a primitive instict: if a blue eyed male and female have a baby, the child has a 100% chance of having blue eyes. Because of this, the male has a better chance at making sure the kid is his. This is interesting because many males don't consciously know this, yet still prefer women with blue eyes!
Besides this, I believe it comes down to preference and what the particular person is used to.
Elizabeth Taylor may have had the most beautiful eyes in the world. They were a rare lavender color. I think this may be the most attractive eye color in the world.
However, when I was in the Caribbean, I noticed some of the residents had remarkable golden eyes, almost like a tiger's eyes. These were also very beautiful and I've never seen this eye color anywhere but in the islands of the Caribbean.
That's a broad question, with a variety of answers...."beauty is in the eye of the beholder", and all that. Different demographics will answer this question differently. A standard middle American might say blue eyes are traditionally the most attractive, but a native Kenyan might think blue eyes are not "normal", and therefore not attractive.
...Well traditionally blue is considered the most attractive, and I tend to agree. But in the end everyone is different and has their own preference.
The reason I personally like blue eyes is because they stand out so much. It's just such a powerful, bright color in a person's eyes.
Personally I don't think there is a most attractive eye color, but instead it depends on the person and specific eyes. Some eyes, no matter what color, are really pretty, and others are much flatter looking. I think it also depends on the person and how the eyes look on the person.
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