Hello, I'm a subject matter expert with a background in genetics and human diversity. Let's dive into the question about redheads and eye color.

English Answer:
No, not all redheads have blue eyes. While it's true that a higher percentage of redheads tend to have blue eyes compared to the general population, eye color is a polygenic trait, meaning it is influenced by multiple genes. Red hair is primarily determined by a variation in the melanocortin 1 receptor (MC1R) gene, which affects the production of pheomelanin, the pigment that gives red hair its distinctive color. However, the melanocortin 1 receptor gene does not directly determine eye color. Eye color is primarily influenced by variations in the OCA2 and HERC2 genes, which are responsible for the production of melanin, the pigment that affects the color of the iris. There is a wide range of eye colors among redheads, including green, hazel, and brown, in addition to blue.

中文回答：
不，并非所有红发人都拥有蓝色眼睛。虽然确实相比普通人群，红发人中拥有蓝色眼睛的比例更高，但眼睛颜色是一个多基因特征，意味着它受到多个基因的影响。红发主要由黑素皮质素受体1（MC1R）基因的变异决定，这个基因影响嗜铬黑色素的产生，嗜铬黑色素是赋予红发其独特颜色的色素。然而，黑素皮质素受体1基因并不直接决定眼睛颜色。眼睛颜色主要受到OCA2和HERC2基因的变异影响，这些基因负责产生黑色素，黑色素是影响虹膜颜色的色素。在红发人群中，眼睛颜色的范围很广，包括绿色、淡褐色和棕色，以及蓝色。

read more >>

Red hair is associated with the gene MC1R, a recessive and somewhat rare gene that occurs in only about 2 percent of the world's population, according to the National Institutes of Health. ... Rarest of all are redheads with blue eyes. The majority have brown eyes or hazel or green shades.read more >>