Refractive Errors : This is the most common type of vision disorder. These are farsightedness, nearsightedness and astigmatism. When any of these happen, eye cannot refract the incoming light properly and the image created appears blurred. Actually these are not eye diseases but refractive errors could affect different age range. Such errors could be corrected using eye glasses, contact lenses and using laser refractive surgery.
Cataract : When transparent lens of our eyes get clouded, it creates blurred vision and this is what cataract is. Most of the cataract cases occur due to aging and it happens slowly. As such there is no preventive measure or cure for cataract using medicines or any kind of optical device but it can be removed using surgery. During surgery, the damaged natural eye lens is removed and instead of it permanent intraocular lens is implanted.
Macular Degeneration : Macula is located in the retina of eyes and needed for central vision. When macular degeneration happens, the center of the picture that the patient sees cannot be brought into focus. In most of the cases, this degeneration happens due to aging and there are two different forms of this vision disorder-wet and dry. Only 10% cases of macular degeneration are wet type and they cause the maximum vision loss. This type of macular degeneration can occur suddenly and patients do not get any warning regarding that. The most important cause is eruption of blood vessels. The dry type of macular degeneration is slow and progressive process. The loss of vision is slow as thinning and tearing of macula happens.
Glaucoma : This vision disorder is caused due to optic nerve problem. When aqueous humor, the clear fluid present in front of the eye, does not drain properly, intraocular pressure keeps on rising thereby optic nerves get damaged and blind spots are developed. When entire nerve gets destroyed it results in blindness. If glaucoma is identified in earlier stages and right course of treatment is followed then complete blindness can be avoided. Early stages of glaucoma have no symptoms. Visible symptoms are loss of peripheral vision and vision loss due to glaucoma is irreversible. This is second most important cause of blindness in developed countries.
Diabetic Retinopathy : It is caused as a side effect of diabetes. When blood sugar level fluctuates it affects blood vessels of different body parts and blood vessels within the retina also get affected. As a result blood vessels tear off and start bleeding and blurred vision is experienced. For the people who have been suffering from diabetes for longer time, there is high risk of retinopathy. Control of diabetes can prevent this disorder. Laser photocoagulation is also used to seal the blood vessels that are leaking.
Retinal Degeneration : This is a broad spectrum word used to describe different hereditary and degenerative visual disorders causing mild to complete blindness. The most common type of retinal degeneration is Retinitis pigmentosa and symptoms occur in childhood or young adulthood days. Patients suffer from night blindness leading to loss of vision.