twe56 I use these things every day. I find that the dial calipers are easier to read for me than the digital ones. The digitals are very sensitive to any movement and will change when removed from the object being measured and give a false reading. Both types are very accurate and either will do the job. You can buy a good 6 inch dial caliper for about $30.00. Hope this helps. BTW I have tri-focals so I know what you mean. Weeds