Dysmetria refers to an inability to judge distance or scale. If a doctor holds up his finger and asks you to touch it, he or she is testing for dysmetria. As you might expect, people who have dysmetria have trouble picking things up (or putting them down in the proper place). Specifically, the patient's hand will take the proper form to pick up the object, but he or she will miss the target. Dysmetria may be seen in patients with schizophrenia or cerebellar trauma, patients with damaged motor neurons (as in multiple sclerosis or ALS), or ophthalmic disorders. You can make yourself temporarily dysmetric by donning a pair of prism goggles, which make things appear as though they're to the left of where they really are.