Eyes are small parts of humans and animals, but they are fascinating.
Take a look at these incredible facts about eyes.
1. Brown Pigment Determines What Eye Color You Have
The one pigment that determines your eye color is brown.
How much melanin in your eyes dictates what color eyes you have.
Those with low amounts of melanin have blue and green eyes, while those with high amounts of melanin have brown eyes.
Other interesting facts about eye color include:
- Eye color cannot be predicted.
- Brown eyes are the most common eye color worldwide.
- People with brown eyes are less likely to develop age-related macular degeneration but are more likely to develop cataracts.
- People with blue eyes are thought to be linked to one common ancestor.
- Blue-eyed people are also thought to have an increased risk of developing a dependence on alcohol.
2. A Blink Can Occur in 1/10 of a Second
The average duration of a blink ranges from 0.1 to 0.4 seconds.
The average time between blinks is 2.8 seconds, so we blink about 21 times in 60 seconds.
3. Your Eyes Can Get Sunburned
Your skin isn’t the only part of you at risk out in the sun. So are your eyes.
The condition is known as photokeratitis.
You can avoid burning your eyes by:
- Reducing exposure to UV light, natural or artificial.
- Wearing sunglasses or hats.
- Spending more time in the shade.
4. A Giant Squid’s Eyes Are 10 Times the Size of a Human’s
A human eye is approximately 1 inch wide, 1 inch deep, and 0.9 inches tall.
In other words, our eyes are about the size of the diameter of a quarter.
The elusive giant squid boasts eyes that are about 10.5 inches across. This is almost a full inch wider than a basketball, with a diameter of 9.55 inches.
5. Camels Have Three Eyelids
Camel eyes protect the animal from its environment.
Two of its eyelids have long lashes to protect against the blowing sand and dust, while its eyebrows are thick and bushy to protect against the sun.
6. Babies Don’t Produce Tears Until They’re 1-3 Months Old
Just because babies cry doesn’t mean tears actually flow.
Babies “only produce enough tears to lubricate and and protect the eye.”
As the glands develop, they will eventually produce streaming tears.
7. Zebras are Mostly Gray to Their Main Predators
The Atlantic’s Ed Yong notes that while we appreciate the zebra’s coat, other animals see it as a blend of gray.
Lions and hyenas, the zebra’s main adversaries, have poorer resolution than humans—so much that humans can spot zebras at twice the distance as lions and more than four times as far away as hyenas.
8. Only 1 in 10 People in Need Have Access to Assistive Products
The World Health Organization says that more than 1 billion people need one or more assistive products to help them see.
This population is only going to grow as the global population ages. More than 2 billion people will need assistive technology by 2030.
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