How much computer use is involved in a mechanical engineer's job?

Most of the engineers I know spend a large amount of time at the computer. The ones in my office spend all of their time at the computer when they are not in meetings. Some engineers at the plants spend a considerable amount of time in the field but they still have to spend about half their time at the computer. This is not bad news for you, however. I assume you have problems with corrective lenses to improve your vision. Computer systems come equipped with adaptation software to help people with poor vision. You can get a larger monitor, as well. Most of us in my office have 19 inch monitors. One guy here with poor vision has a 23 inch monitor (provided by the company) and takes the zoom to 125% or larger to make it easier to see. So don't assume you will be excluded due to vision.