Several national surveys provide data on the prevale nce of vision impairment and blindness . Using age-standardized rates , we can estimate the prevalence of vision impairment and blindness among the general population . Moreover , the prevalence rates of blindness and vision impairment for a given age group ar e comparable .
According to the WHO , there are currently more than 36 million people blind or suffering from severe visual impairment . There are also about 217 million people with moderate or severe visual impairment . Another 1.1 billion people suffer from nearvision impairment , which is corrected by wearing spectacles . The WHO and the VLEG have been working together to monitor change in the prevalence rates of vision impairment and blindness over time . In the last two decades , we have seen a decline in age-standardized blindness and vision impairment .
The prevalence of vision impairment and blindness decreased slightly between 1990 and 2020 . There were only slight increases in the prevalence of moderate and severe vision impairment , primarily due to the fact that resources were targeted toward more severe disease .
Prevention
There are many ways to improve eye health and prevent vision impairment . One of the most effective methods is to prevent vision loss in the first place . People can also develop visual impairment due to eye injuries and diseases . In addition to these , many people are born with some sort of eye defect . These problems can lead to low vision and eventually blindness .
The global burden of vision impairment is enormous . In 2010 , more than 1 bil lion people were blind or had impaired vision due to diseases such as cataract and glaucoma . Near vision impairment is another major cause of vision impairment . The aging population is one of the largest risk factors . People who have vision problems should consider getting their eyes checked regularly .
Eye exams are recommended every two to three years for healthy people . However , people over 50 years of age are advised to see an eye doctor yearly . Having periodic eye exams can also help detect eye problems early . Other tips to protect vision include keeping a healthy weight and diet , and exercising regularly . Also , wearing protective eyewear is important if you engage in activities that can be traumatic to the eye .