Pen Light (no gauge)
The main use of penlight for medical purposes is ‘pupil test’. If a patient suffered a concussion, a penlight is used to make a pupil test. A pupil test is flashing the light straight on the eye to determine its response. Pupil tests are done to understand the severity of a concussion. After passing out, it’s always difficult to tell how intact the brain function and reflexes of a patient is. The easiest way to gauge that is making a pupil test and see how the pupils constrict in presence of light. The doctor or nurse generally matches the constriction against a pupil chart and keep track. Can have several other uses.