Design researcher Dr. Sam Waller points out an interesting conundrum: Most designers have good vision. Or at least, access to corrective measures that enable good vision. Because you can't earn a living manipulating CAD drawings if you can't see them in the first place. What this means is that most designers are automatically designing things that have good visibility only to those with their level of vision and above. This leaves a wide swath of the population behind.
Enter a caption (optional)
While one can always focus-group things amongst folks of different abilities, firsthand experience is always better. That's why Waller and his colleagues at the University of Cambridge's Engineering Design Centre have developed an Inclusive Design Toolkit, which consists of Simulation Glasses and Simulation Gloves that designers can wear to test their own products.
Enter a caption (optional) Enter a caption (optional)
The gloves simulate arthritis, limiting the range of motion and strength of the wearer's digits, while the glasses reduce vision by degrees; stacking on more pairs of glasses reduces visibility further.
The team sells the gloves to designers for £155 (about USD $200) a pair. Five pairs of glasses go for £30 (about USD $40). You can learn more here.