Blindness is the complete or partial loss of vision, also known as vision impairment. In the United States, legal blindness is defined as vision that is worse than 20/200, or vision loss that cannot be corrected using glasses or contact lenses. It can be caused by a number of eye conditions and diseases such as diabetes, glaucoma, cataracts, stroke, and birth complications. Head injuries, injuries to the eye and exposure to certain chemicals and toxins may also cause blindness. In underdeveloped countries, the leading causes include chlamydia (a sexually transmitted disease pregnant mothers can catch and pass down to their newborns), river blindness, and leprosy. It is important to note that 80% of all blindness is preventable or curable, as in cases caused by diabetes or chlamydia.
Blindness includes both partial vision loss, meaning difficulty with vision, or complete vision loss, meaning total lack of vision including an inability to see light at all. The most common symptoms of blindness are loss or lack of vision, cloudy vision, eye pain, and change in eye color. These symptoms can develop rapidly, slowly over time, or be present from birth depending on the cause. Blindness is diagnosed using an eye exam that measures the patient’s clearness of vision, strength of eye muscles, and reaction to light. Treatment for blindness depends on the cause and severity of the condition.
If you experience sudden vision loss, contact a medical professional immediately as this could be a sign of a serious condition. If you have concerns about your vision or have been diagnosed with diabetes, it is important to have regular eye checkups to prevent worsening or loss of vision. If you are pregnant, consult with your doctor to confirm all immunizations are up to date and to screen for sexually transmitted infections before delivery to prevent vision and other problems in your child. Support groups are also available for more resources and information.