What the Difference Between Visually Impaired and Blind?
I have made a YouTube video that goes into depth about the topic. You can watch it below!
There is a wide spectrum of different visual impairments that exist. This ranges from low vision, which can be corrected with glasses and/or contacts to totally blind, where there is no vision or light perception. It is also important to note there is a significant amount of people who are visually impaired with uncorrectable vision meaning glasses, contacts, or other treatments such as surgery cannot improve their vision. Within the spectrum of visual impairments there are some leading causes which include uncorrected refractive errors, cataracts, macular degeneration, diabetic retinopathy, and glaucoma (“WHO | Vision impairment and blindness,”2018). When vision is talked about it is usually referred to with a visual acuity to help understand the severity of the visual impairment.
A measurement of 20/20 visual acuity is considered to be perfect vision. The meaning of this number is if the average person can see an object clearly from 20 feet away, then someone with a visual acuity of 20 can also see the same object from 20 feet away as well. If someone has a visual acuity of 20/200 then that person can see what an average person see from 200 feet away, 20 feet away. Once someone has the visual acuity of 20/300 or 20/400 it becomes inaccurate to measure.
Beyond that point the main distinguishing factors are whether a person has light perception and if they can recognize different shapes or color.
What is a visual impairment? Visual impairment is when a person’s best-corrected [including with glasses or contacts] visual acuity in their better-seeing eye is 20/70 or worse (mild visual impairment) to severe visual impairment [or legally blind] of 20/200 and total blindness at 20/400 (“WHO | Vision impairment and blindness,”2018). According to these definitions, there are an estimated 217 million people are who are moderate to severely visually impaired and 36 million people who are blind (Bourne et al., 2017). There are an estimated 828 million who are nearsighted (“WHO | Vision impairment and blindness,”2018), which means they can see things that are close in proximity to them but have a difficult time seeing things that are farther in the distance. We also need to consider other impairments such as color blindness. “Color blindness affects approximately 1 in 12 men (8%) and 1 in 200 women in the world,” (“Colour Blindness,” n.d.). In addition there are also people who only see a couple of colors or even a monochromatic palette meaning they see everything in one color with shade variations. This just scratches the surface of permanent challenges that exist and we will look at this in more detail later on.