1. Blindness is, in very general terms, a lack of vision. This covers a lot of territory. Most people, when talking about blindness, are referring to total vision loss. In this case, you cannot see anything, including light. Partial blindness refers to very limited vision whereas partial vision loss can be used to refer to any loss of sight.
2. Vision loss can happen suddenly, or it can be a gradual loss over time. Just because you are experiencing vision loss does not mean that you will go completely blind. Many people lose some of their vision without ever becoming legally blind. (In the United States, a person is declared legally blind when their vision is worse than 20/200 without glasses or contact lenses.)
3. There are many different causes for blindness. In the United States, the leading causes are accident or injury, diabetes, and glaucoma. Cataracts is another leading cause of vision loss that generally does not result in complete blindness. With cataracts, vision often becomes cloudy or fuzzy. Diabetes blindness often results in blurry vision and shadows, with missing areas of vision and difficulty seeing at night. Glaucoma usually causes tunnel vision and missing areas of vision.
4. Other common causes of vision loss include blocked blood vessels, birth complications, eye surgery complications, lazy eyes, strokes, and tumors. All of these can cause partial to total blindness. Vitamin A deficiency is another cause of blindness that is particularly common in people living below the poverty line in Vietnam.
5. Blindness can often be treated, depending on the cause. In many third world nations, blindness is mostly caused by a lack of access to vision correctives like glasses. Something as simple as prescribing the right set of corrective lenses will cure these cases. Nutrition deficiencies can also cause blindness and education and dietary changes are often all the cure that is needed.
6. Cataract surgery is a relatively simple and very effective procedure for restoring sight. Other surgeries are less successful. Optic nerve damage is typically not correctible. Retinal detachment can sometimes be fixed through surgery, but if the detachment has been long-standing, the prognosis is not good.
7. Often vision loss after an injury is due to inflammation. Medicated drops or pills can be used to treat this. Often the vision will return after the inflammation goes down. If it does not, there are compensatory techniques that can be learned to, in effect, retrain the eye. If the vision loss involves vision acuity, meaning vision becomes less clear, prescription glasses or contacts may solve the problem. Improved lighting in the patient’s home can also be helpful.
8. If the vision loss involves visual field loss, it means that the patient can no longer see half of their original field of vision, either vertically or horizontally. If this does not go away once the inflammation is gone, the patient can be taught strategies to see the missing field of vision. The most common strategy is to simply train yourself to turn your head differently so that you can scan the area that you can no longer see normally.