Structure of the EYE

 

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How Do Eyes work?​​​

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EYE, with their ability to see, makes them one of the most valuable and complex sensory organ in the human body

• The human eye operates the same way as cameras

• When we focus on an object, the light is reflected and enters the eye through the cornea.

• As the light passes through, the dome-shaped nature of the cornea bends light, enabling the eye to focus on fine details

• The iris controls the light that reaches the eye by adjusting the size of the pupil

• The lens of the eye focuses light. The lens helps the eye to automatically focus on near and distant objects, and also the approaching objects

• The cornea and lens focus light to reach the retina, which is a light-sensitive zone present on the inner lining of the back of the eye.

• The retina converts optical illusion images into electronic signals which are then transmitted by the optic nerve to the visual cortex, which is responsible for the sense of sight.

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Common Eye Disorders and Diseases

Refractive errors are the most common type of eye disorders. They occur when the shape of the eye does not bend light correctly, which keeps the light rays from focusing properly on your retina. The result is blurred vision. Refractive errors can be corrected by eyeglasses, contact lenses or in some cases surgery.

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The most common refractive errors are:

Myopia - Nearsightedness

Hyperopia - Farsightedness

Astigmatism - distorted vision at all distances

Presbyopia - loss of the ability to focus up close

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Other leading causes of blindness and low vision are primarily age-related eye diseases such as age-related macular degeneration, cataract, diabetic retinopathy, and glaucoma. Apart from these, further common eye disorders include amblyopia and strabismus.

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Age-Related Macular Degeneration

Age-related macular degeneration (AMD), is an eye disorder associated with aging and results in damaging sharp and central vision. Central vision is needed for seeing objects clearly and for common daily tasks such as reading and driving. AMD affects the macula, the central part the retina that allows the eye to see fine details.

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Cataract

Cataract, one of the leading causes of blindness and vision loss is a clouding of the eye’s lens. Cataracts can occur at any age because of a variety of causes, and can be present at birth.

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Diabetic retinopathy

Diabetic retinopathy (DR) is a common complication of diabetes. It is characterized by progressive damage to the blood vessels of the retina, the light-sensitive tissue at the back of the eye that is necessary for good vision. Diabetic retinopathy usually affects both eyes. Early diagnosis of DR and timely treatment reduce the risk of vision loss.

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Glaucoma

Glaucoma is a group of diseases that can damage the eye’s optic nerve and result in vision loss and blindness. Glaucoma occurs when the normal fluid pressure inside the eyes slowly rises. With early treatment, we can often protect our eyes against serious vision loss.

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Amblyopia

Amblyopia, also referred to as “lazy eye,” is the most common cause of vision impairment in children. Amblyopia is the medical term used when the vision in one of the eyes is reduced because the eye and the brain are not working together properly. The eye itself looks normal, but it is not being used normally because the brain is favoring the other eye.

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Strabismus

Strabismus involves an imbalance in the positioning of the two eyes. Strabismus can cause the eyes to cross in (esotropia) or turn out (exotropia). Strabismus is caused by a lack of coordination between the eyes. As a result, the eyes look in different directions and do not focus simultaneously on a single point