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So, we now have some idea of how the eye works and the role of Vitamin A in sight. Colour blindness is only one of the problems that may occur in the eye, one that has no real solution. So what are some of the solvable eye problems?  

Conjuctivitis (cornea)

Picture: Ansevilu

This is also known as ‘pink eye’ and is the result of irritation of the clear membrane covering the white part of the eye and interior of the eyelid. There are three general causes:

  • Allergies
  • Bacterial Infection
  • Viral Infection

Viral conjunctivitis usually clears up within a few weeks, while anti-biotic eye drops are used to kill off bacterial infections in the eye. Artificial tears are often used to help prevent the symptoms of allergic conjunctivitis, as they help to dilute any dust or foreign allergy-causing substance in your eye. Anti-histamine pills can also help to control conjunctivitis.

 

Short- or Long-Sightedness

 

Myopia, or short-sightedness, is an eye condition where distant objects appear blurry because light rays are focused to a point in front of the retina.

Hyperopia, or long-sightedness, is the corresponding eye condition that makes close objects appear blurry because light rays are focused behind the retina.  

These conditions are caused either because the cornea is too curved or flat, respectively, or by an unusually shaped eyeball.

Traditional methods of dealing with short- and long-sightedness include glasses and contact lenses.

In the case of short-sightedness, a concave lens in the glasses is used to move the point where the light converges from the middle of the eye to the retina.

In long-sightedness, a convex lens is used to move the focus point of light forward onto the retina rather than behind the eye.

Specially trained eye surgeons are now able to use laser technology to re-shape the cornea of the eye. This removes the need for corrective glasses or contact lenses.

For further information about correcting short- or long-sightedness, see

http://www.allaboutvision.com/visionsurgery/other.htm

http://www.medicinenet.com/lasik_eye_surgery/article.htm

 

Cataract

A cataract is when the lens of the eye becomes cloudy. A cloudy lens prevents light from going through the lens to the retina and so blindness ultimately results.

According to the World Health Organisation cataracts are the leading cause of blindness, being responsible for 48% of blindness in the world.

Most cataracts are caused by aging. Because the lens in the eye is made up of mainly protein and water, as it ages the carefully-arranged proteins can clump together, clouding the lens.  

Occasionally children are born with a cataract or one may develop after eye injury, inflammation or some other eye disease.

Cataracts are treated by surgery to remove the clouded lens and replace it with a synthetic one. This synthetic lens can be concave or convex in order to fix short- or long-sightedness at the same time as restoring sight.

For more information, refer to:

http://www.vision2020.org/main.cfm?type=WIBCATARACT

http://www.who.int/blindness/Vision2020_report.pdf

Understanding better how the eye works, from both a biological and chemical perspective, has led to important discoveries about how to improve night vision and prevent blindness.

Eye conditions such as conjunctivitis, short-and long-sightednesss and cataracts can be successfully treated using a variety of methods. Vitamin A is now deliberately added to food while lens and laser surgery are restoring sight.

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