Gray eyes and blue eyes are both unique and beautiful eye colors. Here are some details about each:

Gray eyes:

• Gray eyes are very rare and are present in only 3% of the worlds population.
• The color and intensity of gray eyes can vary from person to person and can include dark gray, gray-green, and gray-blue.
• Gray eyes may appear to change color from gray to blue or green depending on the lighting and surroundings.
• Gray eyes may have flecks of gold and brown, and they may appear to have a cloudy or hazy appearance.
• The appearance of gray eyes may be due to larger deposits of collagen in the stroma, which causes light to undergo Mie scattering rather than Rayleigh scattering.

Blue eyes:

• Blue eyes are generally recessive and are the second most common eye color in the world, with an estimated 17% of the population having blue eyes.
• Blue eyes have a low level of pigment present in the iris, which causes light to reflect off the protein collagen in the stroma, giving them their blue appearance.
• People with blue eyes may have a higher risk of light sensitivity, especially those with albinism.
• Scientists have found that everyone with blue eyes is related due to various racial groups intermarrying.

There are no positive or negative aspects associated with having gray or blue eyes, and there are no specific ingredients or materials that make up these eye colors. Eye color is determined by complex genetics and the presence of melanin in the iris.