A cataract is a clouding that develops in the crystalline lens of the eye or in its envelope, obstructing the passage of light. Cataracts typically progress slowly to cause vision loss and are potentially blinding if untreated. Cataracts develop for a variety of reasons, including long-term exposure to ultraviolet light, exposure to radiation, secondary effects of diseases such as diabetes, hypertension and advanced age, or trauma. Genetic factors are often a cause of congenital cataracts and positive family history may also play a role in predisposing someone to cataracts at an earlier age. The most effective and common treatment is to make an incision (capsulotomy) into the capsule of the cloudy lens in order to surgically remove the lens. The cataractous lens is removed and replaced with a plastic lens (an intraocular lens implant) which stays in the eye permanently.
The agonizing Trachoma starts off like conjunctivitis and ends up with broken bits of eyelash scraping continually against the inside of the eye. Trachoma is responsible for nearly 4.9 million blind, mainly as a result of corneal scarring and vascularization. The disease is known to devastate entire villages at a time. The continual scraping of the corneas due to trachoma is one of the major causes of blindness among the Hamar people.
Vitamin A deficiency (VAD) is a disease largely of the lowest socioeconomic populations in developing countries where food choices are limited. Malnutrition in children may be a continuation of an undernourished state that began in infancy or it may arise from factors that become operative during childhood.
In Ethiopia, the nutritionally inadequate weaning diet and overcooking of limited green leafy vegetables predispose to VAD. A recent survey of third and fourth grade school children in Ethiopia demonstrated the higher risk in children that had not eaten vegetables or fruits on the day prior to the survey.
Xerophthalmia is the leading preventable cause of blindness worldwide and is associated with increased mortality in children 6 months of age and older.
Vitamin A supplementation can effectively reduce total mortality in susceptible populations.
According to the United Nations Children’s Fund, an estimated 84 % of children in Ethiopia aged 6–59 months received at least one high-dose vitamin A capsule in 2010 . However, it is estimated that in rural areas preschool children, are at risk of xerophthalmia.
There are an estimated 1.4 million blind children worldwide. There is a wide regional and socioeconomic variation in the etiology of childhood blindness, but it is estimated that 200,000 children are blind from cataract, with an additional 20,000-40,000 born each year with congenital cataract. A VISION 2020 report estimated that 133,000 cataract blind children live in developing countries. The prevalence of cataract as a cause for severe visual impairment and blindness may reach over 30% of cases in the developing world, and it is considered to be one of the most common causes of avoidable and treatable blindness following vitamin A deficiency, measles and corneal scarring. With basic preventative healthcare measures such as immunization and nutritional supplementation being implemented, these causes of blindness should decrease and cataract will likely become even more prominent.
Corneal visual impairment encompasses a wide variety of infectious and inflammatory eye diseases that cause scarring of the cornea, the clear membrane that covers the outside of the eye. Significant scarring ultimately leads to functional vision loss.
The 4th cause of blindness globally (5.1%), corneal blindness is one of the major causes of visual deficiency after cataract, glaucoma and age-related macular degeneration (AMD). Trachoma is responsible for nearly 4.9 million blind, mainly as a result of corneal scarring and vascularization. Ocular trauma and corneal ulcerations are significant causes of corneal blindness. They are often underreported but they are estimated at 1.5 to 2.0 million new cases of unilateral blindness every year. Among the causes of childhood blindness (approximately 1.5 million cases in the world and 5 million children with visual impairment) appear xerophthalmia (350,000 cases per year), newborn conjunctivitis, and rarer ocular infections like herpes and keratoconjunctivitis.
Traditional eye medicines have also been implicated as a major risk factor in the current epidemic of corneal ulceration in developing countries.