Eye Facts


Source: National Institutes of Health (NIH)


Although the eyes are small compared with most of the body’s other organs, their structure is incredibly complex. Before taking a look at how the eye works, let’s start with a basic overview of structures that make up the eye and its function.

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Part of the Eye Functions
  • The clear, dome-shaped surface that covers the front of the eye
  • Allows light to enter eye
  • The coloured part of the eye
  • Controls the size of the pupil
  • The opening in the centre of the iris
  • Controls the amount of light that enter the eye
  • Composed of transparent, flexible tissue
  • Helps to focus light and images on your retina
  • The light-sensitive tissue that lines the inside surface of the eye
  • “Photo receptor” cells and the retina converts light into electrical impulses
Optic nerve
  • A bundle of about one million nerve fibers
  • Carries electrical impulses to the brain
  • The small sensitive area in the center of the retina
  • Provides clear central vision
  • Located in the centre of the macula
  • Provides the sharpest detail vision
Vitreous gel
  • The jelly like substance that fills the inside of the back part of the eye (in between the lens and the retina)

1. American Foundation for the Blind.
2. National Eye Institute.

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Light rays enter the eye through the cornea, the clear front “window” of the eye. The iris of the eye functions like the diaphragm of a camera, controlling the amount of light reaching the back of the eye by adjusting the size of the pupil automatically.


The pupil dilates (enlarges) and constricts (shrinks) like the aperture of a camera lens as the amount of light in the immediate surroundings changes. In dark conditions, the pupil widens. In bright conditions, the pupil constricts.


After passing through the iris, the light then goes through the eye’s natural crystalline lens. Just like the lens of a camera, the lens of the eye focuses the light or an image onto the retina. The lens becomes thicker to focus on nearby objects and thinner to focus on distant objects.


The retina acts like an electronic image sensor of a digital camera, converting optical images into electronic signals. The optic nerve then transmits these signals to the brain.



Your eyes are an important part of your health. There are many things you can do to keep them healthy and to ensure you are seeing your best.

Follow these simple steps for maintaining healthy eyes well into your golden years.


A dilated eye exam is the only way to detect many common eye diseases such as glaucoma, diabetic eye disease and age-related macular degeneration (AMD) in their early stages.

Vegetables and fruits naturally contain carotenoid antioxidants lutein and zeaxanthin that protect your eyes against the sun’s intense ultraviolet (UV) rays and harmful blue lights from digital screens of smart phone, television, computer and tablet screens. These two carotenoid antioxidants are also important for maintaining healthy eyesight and sharper vision. Lutein and zeaxanthin help reduce the risk of eye diseases, such as AMD or cataracts.

Besides that, vitamin C, vitamin E and omega-3 fatty acids are important nutrients for maintaining healthy eyes.

Try eating these foods regularly:-

  • Lutein- and zeaxanthin-rich vegetables: Spinach, kale
  • Vitamin C-rich fruits: Oranges, papaya, grapefruits and other citrus fruits
  • Omega-3 fatty acids-rich fishes: Salmon, tuna, mackerel

Being overweight or obese increases your risk of developing type 2 diabetes; this can lead to diabetic eye disease, glaucoma or blindness.

Smoking is as bad for your eyes as it is for the rest of your body. Research has linked smoking to an increased risk of developing AMD, cataract, and optic nerve damage, all of which can lead to blindness.

Sunglasses are important to protect your eyes from the sun’s ultraviolet (UV) rays, which can be dangerous even on cloudy days. Overexposure to UV radiation increases your risk of getting cataracts and macular degeneration. The American Optometric Association recommends sunglasses that block both UVA and UVB radiation, screen out 75 to 90 percent of visible light, are free of imperfections and distortion, and have grey lenses for proper colour recognition.

If you spend a lot of time starring at digital screens from laptops to smartphones or even long periods focusing on any one thing, you sometimes forget to blink and your eyes can get fatigue. Blinking is how you bring fresh tears to the corneal surface, which helps your eyes stay moist and free of irritants. Try the 20-20-20 rule: Every 20 minutes, look away about 20 feet in front of you for 20 seconds. This can help reduce eye strain. Besides that, at least every 2 hours, get up and take a 15-minute break.

To avoid the risk of infection, always wash your hands thoroughly before putting in or taking out your contact lenses. Ensure that you clean and store your lenses only in fresh solution and replace them as directed.

Being physically active can delay the onset of age-related macular degeneration, which is the leading cause of blindness later in life.

With enough water, you can produce enough tears to keep your eyes moist and nourished.

» view references

1. National Eye Institute. Simple Tips for Healthy Eyes.
2 .Everyday Health. 9 Simple Ways to Keep Your Eyes Healthy.
3. WebMD. 10 Tips for Healthy Eyes.

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Where to buy?

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