11 Fascinating Eye Facts You Need to Know

Do you know how fast you blink or why brown eyes are so common? Dive into these and other eye facts that reveal just how extraordinary your eyes really are.

We are covering 11 surprising facts about eyes, offering insights that range from the science of blinks to the mysteries of eye colour.

The Speed of a Blink

Blink, and you might miss it – literally! The human eye can blink at an astonishing speed, with each blink lasting only about 1/10th of a second. This rapid action serves as a crucial protective mechanism for our eyes, helping to keep them moist and clear of debris. But have you ever wondered how many times we blink in a day?

On average, most adults blink between 14 to 17 times per minute, which adds up to a staggering 13,440 to 16,320 blinks in a single day, assuming 8 hours of sleep. Some estimates suggest that we blink up to 28,000 times a day! This constant, almost imperceptible action is a testament to our eyes' tireless work to maintain our vision. The average person blinks quite frequently without even realizing it.

As you delve deeper into the wonders of our eyes, remember that you’ve likely blinked numerous times just reading this!

Brown Eyes Dominance

When it comes to eye colour, brown reigns supreme across the globe, more than half of the world’s population boasts brown eyes, making it the most common eye colour by far. This prevalence is due to the dominant nature of the gene responsible for brown eyes. But why are brown eyes so widespread, and how did other eye colours come to be?

Interestingly, all humans originally had brown eyes until a genetic mutation occurred, leading to the emergence of blue, green, and hazel eyes. Scientists believe that the first blue-eyed individual appeared around 6,000 years ago, marking a significant milestone in human genetic diversity. This mutation altered the OCA2 gene, which is responsible for producing melanin in the iris. The result? A beautiful spectrum of eye colours that we see today, including blue eyes among blue-eyed people, with brown eyes remaining the most common due to their genetic dominance.

Computer Vision Syndrome

In our increasingly digital world, our eyes are facing new challenges. Computer Vision Syndrome (CVS) is a modern-day ailment that affects countless individuals who spend long hours staring at screens. This condition can cause a range of symptoms, including:

  • eye strain
  • dryness
  • itchiness
  • redness
  • blurred or double vision

The root of the problem lies in how screens force our eyes to constantly focus and refocus, while the brightness and glare make our eyes work even harder.

But the effects of CVS aren’t limited to just our eyes. Many people also experience backaches, neck aches, and muscle fatigue as a result of prolonged screen time. To combat these issues, it’s essential to take regular breaks, adjust screen settings, and ensure proper ergonomics. Additionally, reducing glare and harsh reflections on computer screens can significantly help mitigate CVS symptoms.

Read more about CVS and how to manage it in our blog, Eye Strain Solutions!

Curable and Avoidable Vision Problems

Here’s an eye-opening fact: more than 80% of vision impairment in Canada can be prevented or cured. From simple refractive errors correctable with glasses to more complex conditions like cataracts, many vision issues have effective treatments available.

Simple solutions like eye tests, glasses, and cataract operations can alleviate most vision loss cases. Book an eye exam with to stay ahead of your eye care.

Eye Information Processing

Our eyes are incredible information processors capable of handling an astonishing amount of data in a short time. The human eye can process a staggering 36,000 pieces of information in a single hour. This remarkable ability allows us to:

  • Rapidly take in and interpret our surroundings
  • Distinguish between different colours and shades
  • Perceive depth and distance
  • Track moving objects
  • Recognize faces and facial expressions

These functions, including depth perception, contribute significantly to our perception of the world.

The importance of vision in our cognitive processes cannot be overstated. Approximately half of the human brain is dedicated to vision and seeing, highlighting our eyes' crucial role in our overall neural function.

Moreover, about 80% of our memories are determined by what we see, underscoring the profound impact visual information has on our ability to form and retain memories. Given the vital role our eyes play in processing information and shaping our experiences, it’s clear why regular eye exams are crucial for maintaining eye health and preventing serious issues.

The Mystery of Emotional Tears

Tears are a uniquely human expression, often associated with strong emotions. Yet, despite their ubiquity in human experience, we still don’t fully understand the biological link between crying and emotions. What we do know is that emotional tears arise from intense feelings such as empathy, compassion, and attachment pain. These tears, which produce tears different from other types, contain higher levels of stress hormones and natural painkillers.

As we continue to unravel the mysteries of emotional tears, it’s clear that this uniquely human trait plays a complex role in our emotional and social lives.

Visible Part of the Eye

When we look into someone’s eyes, we’re only seeing a small fraction of this complex organ. In fact, only about 1/6th of the human eye is visible from the outside. This visible portion includes the cornea, which is approximately 11.5 mm in diameter and serves as the eye’s protective outer layer. The cornea, along with the iris and lens, make up what’s known as the anterior segment of the eye.

While we may only see a small part of the eye, each visible component plays a crucial role in our vision. The conjunctiva, a thin layer sitting on top of the visible part of the eye, helps keep it moist and protected. The iris, with its dilator and sphincter muscles, constantly adjusts the size of the pupil to control the amount of light entering the eye. These intricate structures work in harmony to enable our vision, reminding us that there’s much more to our eyes than meets the eye.

Blind Spots in Vision

Surprisingly, our eyes have small blind spots where we can’t see anything at all. These blind spots occur where the optic nerve passes through the retina, creating areas that lack light-sensitive cells. While this might sound alarming, these blind spots are actually quite small – approximately the size of a pinhead. The blind spot is caused by the optic disk, a location where the optic nerve exits the eye and blood vessels enter, leaving no room for light-sensitive cells.

Despite these gaps in our vision, we rarely notice them in our day-to-day lives. This is because our brains are remarkably adept at filling in the missing information. Our eyes work together, using information from the opposite eye to fill in gaps created by blind spots. Additionally, the brain can fill in the missing information using visual cues from the surrounding environment. This clever trick of the brain ensures that we perceive a seamless, uninterrupted view of the world around us, even with these small blind spots in our vision.

Continuous Functioning of Eyes

Our eyes are constantly at work, even when we’re fast asleep. Surprisingly, our eyes continue to see light even when we’re in the land of dreams. This continuous functioning plays a crucial role in regulating our sleep-wake cycle. During sleep, our eyes can sense changes in light levels, which can potentially wake us up. This is why maintaining a dark room is essential for better sleep quality, as our eyes can detect light even when closed.

Interestingly, our eyes behave differently during various stages of sleep. During Rapid Eye Movement (REM) sleep, our eyes move in all directions, but they don’t send visual data to the brain. This phenomenon is part of the complex processes that occur during sleep, including dream formation and memory consolidation.

The relentless operation of our eyes, even while sleeping, emphasizes their crucial function not only in sight but also in overall physiological regulation and wellness, including night vision capabilities.


Impact of Diabetes on Eyesight

Diabetes can have a significant impact on eye health, potentially leading to severe eyesight issues such as diabetic retinopathy. This condition occurs when high blood sugar levels damage the tiny blood vessels in the retina. What makes diabetic retinopathy particularly concerning is that its early stages often have no symptoms, underscoring the importance of regular eye exams for individuals with diabetes.

The effects of diabetes on eye health extend beyond retinopathy. Diabetes significantly increases the risk of other eye conditions like cataracts and open-angle glaucoma. 

Pregnant women with diabetes are at higher risk for diabetic retinopathy and should have early and regular eye exams. 

Understanding colour Blindness

Colour blindness, a condition that affects the perception of colours, is more common than many people realize. Approximately 1 in 12 men and 1 in 200 women globally are affected by some form of colour blindness. This condition is usually inherited genetically and typically passed down from the mother. The human eye perceives colour through a combination of red, blue, and green receptors, and colour blindness occurs when one or more of these receptor types are affected.

The most common form of colour blindness is red-green colour blindness, where individuals have difficulty distinguishing between colours that contain red or green. This can impact the recognition of various colours, including:

  • Reds
  • Greens
  • Oranges
  • Browns
  • Purples
  • Pinks
  • Greys
  • Sometimes even black

Interestingly, people with severe forms of colour blindness may not realize the extent of their condition due to their reliance on coping strategies.

It’s worth noting that approximately 40% of colour-blind pupils leave school unaware of their condition, highlighting the importance of early detection and awareness.


As we’ve journeyed through these 11 fascinating eye facts, it’s clear that our eyes are truly remarkable organs. From the lightning-fast speed of a blink to the complex process of colour perception, our eyes are constantly working to help us navigate and understand the world around us.

By understanding and caring for our eyes, we can ensure that we continue to see the beauty and wonder of life in all its vivid detail.

Frequently Asked Questions

How often should I have my eyes checked?

To maintain good eye health, it's recommended for adults with no vision problems to have a comprehensive eye exam every 1-2 years, while those with existing eye conditions or risk factors may need more frequent check-ups. Children should have their first eye exam between 6-12 months of age, then at three years old, and before starting school.

Can staring at screens really damage my eyes?

Yes, staring at screens can lead to Computer Vision Syndrome (CVS), causing symptoms like eye strain, dryness, and blurred vision. To reduce these effects, follow the 20-20-20 rule.

Is it true that carrots improve eyesight?

Carrots do not directly improve vision, but a diet high in vitamins A, C, and E, as well as omega-3 fatty acids, can support overall eye health and may help prevent age-related eye diseases.

Can eye exercises improve vision?

Eye exercises can help with eye strain and focus, but they cannot correct refractive errors, for conditions like nearsightedness or farsightedness, corrective lenses or surgery are needed to improve vision.

Is it bad to read in dim light?

Reading in dim light can cause eye strain and discomfort, but it doesn't damage your eyes. Good lighting reduces the effort your eyes need to make, making reading more comfortable. If you frequently need very bright light to read, it might be time for an eye exam.

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