People that have low vision can see but their vision is still quite far from perfect even with powerful lenses. They can’t see well enough to drive or read most printed text without enlarging it. It is difficult for them to see well enough to read small fonts and faces and objects appear blurry.
Here are a few possible types and characteristics:
- Blur with Low Contrast
- Cataracts
- Diabetic Retinopathy
- Glaucoma
- Hemianopia
- Macular Degeneration
- Retinal Detachment
How Low Vision People use their computers?
With Screen Magnification [Software for low vision users]
One of the main technologies for people with low vision is a screen magnifier. Screen magnifiers increase the size of the parts of the screen, just like a magnifying glass would so that the text and the images on the screen are easier to see.
However large magnification is very useful and can deal with the main challenges of low vision, there are still some issues a user can encounter.
Issues:
If an image is particularly large, a user may need to scroll around the screen to see the whole thing.
If a JavaScript alert pops up to the side of the current visual focus, the alert may actually appear out of the visible area for the user with low vision, so the user may not see the alert at all. It is best to place popups, alerts, error messages, and other similar messages near the visual focus, to make sure users don’t miss them.
For people with low color vision, colors may not be easily visible, and may be difficult to differentiate from each other.
Text that is too near in color or brightness to the background can be hard to read.
Some people may also experience pain when looking at bright lights or bright areas on paper or
Different Types Of Screen Magnifications:
Zoom Text +MAGic
They have a large number of features to help low vision people and enhance their visual experience.
Design Considerations for Low Vision
1 Zoom Feature should not be disabled
The pinch-to-zoom feature should be enabled. When zooming is not able on a web page, low vision users who use screen magnifiers to read text may be not able to correctly see information on a web page.
2 Color contrast must be checked by any tool or browser extention.
All content color contrast must be checked by any tool or browser extention.
Some low vision users may see in low contrast. So, text, borders, and other elements may look same or similar shades of brightness to them. Textual elements that are too close in brightness to background colors may be extremely difficult to read for these users.
3 Visual and hover state both must be present.
Links, buttons, and controls must have a visible: focus state and should have a visible: hover state. Some people who have low vision may use a keyboard or a mouse, or both, as input methods. Having visible: focus and: hover states help users to know where the keyboard/mouse focus is on a web page. Low vision users benefit greatly from enhanced CSS: focus and: hover states.
4 provide a clear visual distinction between content (e.g., text) and controls (e.g., buttons, links, etc.).
The user interface should provide a clear visual distinction between content (e.g., text) and controls (e.g., buttons, links, etc.).
5 Do Not Use Color Alone to Communicate Information
Make sure the important information is represented in the text and not with the color only.
