Causes of Blindness and Visual Impairment
Ages: 15+ (adapt with provided resources)
Time: 1-2 Class periods
Learning Objectives:
Students will research different causes of visual impairment and blindness
Materials: Terms to Research and Answer Key; Internet-enabled devices for research
Background
Being blind doesn’t mean that all you see is blackness. Most blind people—about 90%—have a little vision. Some are able to see colors and others see shadows, or at least the difference between light and dark.
Globally, at least 2.2 billion people have a vision impairment or blindness, of whom at least 1 billion have a vision impairment that could have been prevented or has yet to be addressed. This is more than ¼ of the population.
These 1 billion people include those with moderate or severe distance vision impairment or blindness due to unaddressed refractive error, as well as near vision impairment caused by unaddressed presbyopia.
Globally, the leading causes of vision impairment are uncorrected refractive errors and cataracts.
The majority of people with vision impairment are over the age of 50 years.
Steps:
Activate: Ask students to give their best guess about some of the statistics above. Example: what percentage of the global population has some kind of visual impairment including blindness? Ask what stats surprise them, and discuss why.
Have students research in pairs the causes of visual disabilities to complete the matching activity that follows. High school students can be assigned one of the following causes of vision loss: macular degeneration, ocular histoplasmosis syndrome, cataracts, glaucoma, Retinitis Pigmentosa, diabetic retinopathy, optic nerve hypoplasia, trachoma, Retinopathy of Prematurity, onchocerciasis, refractive errors, strabismus, retinal detachment, and cortical impairment. Younger students can use the matching worksheet included. Use these sources:
Research Extension: for students who finish early or whole-group extension:
How do the countries where people live affect the reasons why they may have a visual disability? Keep track of your sources!
How do people’s ages affect the reasons why they may have a visual disability?