The human eye is a remarkable feature that receives light, allowing a viewed object to be transmitted as messages to the brain so that we understand what we see. It can detect something as small as a candle flame from up to 15 miles away (under optimum conditions) as well as focus on fine details. A pity, then, when this 'window to the soul' is allowed to degenerate.

Not all eye diseases are caused by negligence but a large percentage is. Strain, an unbalanced diet, a poor lifestyle, lack of awareness and bad habits can contribute to diminishing the wonders our eyes offer.

Certain eye conditions are common, some developed through the natural process of aging and others caused by disease, injury and exposure to chemicals. Let's see what they are.

Age-related

Age-related conditions include glaucoma, cataract, age-related macular degeneration and diabetic retinopathy.

Glaucoma: With glaucoma, peripheral vision is compromised as the optic nerve is affected. It creates tunnel vision of sorts. The main causes are genetics with a family history signaling a greater risk factor, severe eye infection, injury and blockage of blood vessels. Diet has not been known to play a role though people suffering from the condition can see it exacerbate with caffeine in intake.

Medication through eye drops and surgery are recommended treatments although once vision starts to fade it can not usually be recovered, only halted.

Cataract: Where glaucoma creates tunnel vision, cataract impairs overall vision to make it blurry or cloudy. Light is unable to properly pass through to the retina. The condition progresses slowly and is marked by a literal clouding of the pupils and irises.

Cataract is caused by age and more uncommonly, by trauma, genetics, drug use and nutrition-related diseases. It's typically resolved through surgery which can restore a large percentage of vision unlike with glaucoma.

AMD: Age-related macular degeneration is primarily caused by old age. Where glaucoma affects the peripheral vision, AMD targets the central vision. As such, blindness is rarely caused although vision impairment is naturally present and may progress without treatment.

Treatment typically involves laser surgery, implanting a telescopic lens and increasing vitamin intake.

AMD presents itself in one of two forms – dry and wet. Dry AMD sees the macula (an area near the retina) thinning to affect central vision. It's the more common form and progresses slowly. In wet AMD, blood vessels behind the retina begin to grow under the macula to lead to leakage of blood and fluid as well as scarring which further diminishes central vision.

Diabetic retinopathy: A common complication in diabetic patients, diabetic retinopathy occurs due to damage to the retinal blood vessels. Proper diabetes management through control of blood sugar, blood pressure and other necessary symptoms can see the condition brought to a halt and even reversed to an extent.

Infection-related

Where age plays no role, conditions like conjunctivitis, sty and uveitis should be watched for. Conjunctivitis can be caused by chemical irritants, viruses and bacteria and even pollution. Sties, meanwhile, are caused by an infection of the oil glands in the eyelid. Both are fairly common and easy to treat with emphasis laid on keeping the affected eye clean and following a medical prescription.

Uveitis, on the other hand, is a potentially serious condition with the ability to cause blindness if left untreated. Risk factors include infections, injury, cancers like lymphoma and autoimmune diseases. Depending on cause, treatment can include medication or surgery.