Eye care is an important fact of life. Many people seek vision correction techniques from wearing eyeglasses and contact lenses to having LASIK and cataract surgery. On the other end of the spectrum, there are many interesting facts about eyes you probably didn’t know about. Eyes are among the most complex organs in the body, as you’ll see with these facts about eyes we have compiled.

The Eye Is an Ancient Phenomenon

The first eyes appeared over 550 million years ago. Primitive lifeforms didn’t have eyeballs like humans and many animals do. Instead, single-celled organisms had patches of photoreceptor proteins that could detect light.

Eyes Are Complex

The second most complex organs after the brain, eyeballs have over 2 million working parts. More than 1 million nerve fibers connect each one to the brain.1 This currently makes it impossible to transplant eyes. However, transplant surgeons in Pittsburgh predicted in 2016 that, based on advances in surgical techniques and immunosuppressive drugs, it may be possible to transplant an eye from a deceased donor to a recipient and restore vision, by 2026.2

Eyes Are Well-Protected

Eyebrows prevent sweat from reaching your eyes, while eyelashes serve to keep dirt out of them. Eyelashes are also continuously shed, lasting approximately 5 months each and adding up to over 98 feet of shed hair per eye over a person’s lifetime.3 The conjunctiva, a thin membrane that covers the white of the eye and underside of the eyelid, prevents objects from reaching behind the eyeball. That’s why contact lenses cannot get stuck behind your eye.

Eye Muscles Are the Body’s Fastest

There are six extraocular muscles attached to each eye, allowing you to look side to side. Responsible for a variety of involuntary motions, they allow movements called saccades that last 50 to 60 milliseconds each.4 In fact, saccades can be used to predict a person’s decisions, per studies conducted with participants observed selecting options on a computer screen.

Newborn Babies Have Limited Color Vision

The myth that babies see in black and white has been around for a while. Newborns also see in shades of gray and can detect red objects as well. An infant’s color vision is limited because the photoreceptor cells, or cones, in the eyes aren’t yet strong enough. Babies typically gain the ability to tell apart red and green at two months and blue and yellow a few weeks after that.

Eye Length Partly Determines Visual Acuity

human eye model

Aside from cornea and lens shape, visual acuity is also determined by whether your eyeball is too long or short. This isn’t often considered with eye surgery. If your eyes are longer than average, you’re likely nearsighted. But if your eyes are shorter, you’re probably farsighted. This is because, along with the cornea and lens, eye length affects light refraction within the eyeball.

Schedule Corrective Eye Surgery with ADV Vision Centers

At ADV Vision Centers, located in Paso Robles, Santa Maria, and San Luis Obispo, CA, we can provide cataract, LASIK, and other eye surgeries as well as glaucoma treatment and a range of ophthalmological services. Contact us online for a free consultation or call 805-987-5300 today and schedule an appointment.


  1. https://discoveryeye.org/20-facts-about-the-amazing-eye/
  2. http://mentalfloss.com/article/563242/parts-of-the-eye-facts
  3. https://discoveryeye.org/20-facts-about-the-amazing-eye/
  4. http://mentalfloss.com/article/563242/parts-of-the-eye-facts