Also, according to the Saudi Journal for Health Sciences, sometimes patients experience irreversible amblyopia after pediatric cataract surgery because the cataracts prevented the normal maturation of vision prior to operation. Despite the great progress in treatment, cataracts remain a global problem in both economically developed and developing countries. At present, with the variant outcomes as well as the unequal access to cataract surgery, the best way to reduce the risk of developing cataracts is to avoid smoking and extensive exposure to sun light (i.e. UV-B rays). Glaucoma
Glaucoma is an eye disease often characterized by increased pressure within the eye or intraocular pressure (IOP). Glaucoma causes visual field loss as well as severs the optic nerve. Early diagnosis and treatment of glaucoma in patients is imperative because glaucoma is triggered by non-specific levels of IOP. Also, another challenge in accurately diagnosing glaucoma is that the disease has four causes: 1) inflammatory ocular hypertension syndrome (IOHS); 2) severe uveitic angle closure; 3) corticosteroid-induced; and 4) a heterogonous mechanism associated with structural change and chronic inflammation. In addition, often pediatric glaucoma differs greatly in cause and management from the glaucoma developed by adults. Currently, the best sign of pediatric glaucoma is an IOP of 21 mm Hg or greater present within a child. One of the most common causes of pediatric glaucoma is cataract removal surgery, which leads to an incidence rate of about 12.2% among infants and 58.7% among 10-year-olds.
Cause
The most common causes of visual impairment globally in 2010 were:

Refractive error (42%)
Cataract  (33%)
Glaucoma (2%)
Age-related macular degeneration (1%)
Corneal opacification (1%)
Diabetic retinopathy (1%)
Childhood blindness
Trachoma (1%)
Undetermined (18%)The most common causes of blindness worldwide in 2010 were:

Cataracts (51%)
Glaucoma (8%)
Age-related macular degeneration (5%)
Corneal opacification (4%)
Childhood blindness (4%)
Refractive errors (3%)
Trachoma (3%)
Diabetic retinopathy (1%)
Undetermined (21%)About 90% of people who are visually impaired live in the developing world. Age-related macular degeneration, glaucoma, and diabetic retinopathy are the leading causes of blindness in the developed world.Among working-age adults who are newly blind in England and Wales the most common causes in 2010 were:
Hereditary retinal disorders (20.2%)
Diabetic retinopathy (14.4%)
Optic atrophy (14.1%)
Glaucoma (5.9%)
Congenital abnormalities (5.1%)
Disorders of the visual cortex (4.1%)
Cerebrovascular disease (3.2%)
Degeneration of the macula and posterior pole (3.0%)
Myopia (2.8%)
Corneal disorders (2.6%)
Malignant neoplasms of the brain and nervous system (1.5%)
Retinal detachment (1.4%)

Cataracts
Cataracts are the greying or opacity of the crystalline lens, which can be caused in children by intrauterine infections, metabolic disorders, and genetically transmitted syndromes. Cataracts are the leading cause of child and adult blindness that doubles in prevalence with every ten years after the age of 40. Consequently, today cataracts are more common among adults than in children. That is, people face higher chances of developing cataracts as they age. Nonetheless, cataracts tend to have a greater financial and emotional toll upon children as they must undergo expensive diagnosis, long term rehabilitation, and visual assistance.