Manual thermostats are still installed because they can be easily set and read by those who can't see, or who have limited vision. Digital thermostats are referred to as digital because they have an LCD (liquid crystal display) screen. Some manual thermostats even have enlarged, raised numbers that indicate temperature range on special easy-to-see dials. Even regular manual thermostats can be used in sight-challenged situations because there's distinct audible click as the temperature reaches the set point. The click can be used in adjusting the thermostat.
Turn the transparent dial on an sight-assisting manual thermostat until the setting you want on the upper scale is aligned with the pointer. On Honeywell's brand, Easy-to-See, the large, embossed 5, 6, 7 and 8 indicate 50, 60, 70 and 80 degrees. Other brands are similar.
Feel the click every two degrees and the deeper indent at 10-degree points.
Move the lever to the right to increase the temperature and to the left to lower it in the case of a non-Easy-to-See thermostat. If you can't see the numbers, listen for an audible click as you move the lever. The click indicates the set point is at the ambient room temperature. Simply move the lever left or right in increments until you are able to judge the temperature change. All the way to the left is the minimum temperature and all the way to the right is the maximum temperature. This system works on all manual thermostats.