There has recently been an increase in medical accidents occurring in hospitals in which disinfectants have been mistaken for medications. One cause for this problem is considered to be the visibility of the medicine name on the bottle of disinfectants. We therefore examined whether or not the name displayed on the bottles of disinfectant were clearly displayed. We investigated the width of the medicine name currently displayed on bottles of commercial disinfectants and devised a new method to evaluate whether or not the name displayed on the bottle could be easily read from various angles. The evaluation of the width of the medicine name displayed on the bottles was performed by the central angle computed from the length of the arc of the medicine name displayed on the bottle. When 30 subjects viewed the medicine name from a horizontal direction, it became clear that the central angle with the most visible medicine name was from 68 degrees to 90 degrees. It was thus proven that the central angle, visual observation distance and the character font were clearly important factors regarding the visibility of the medicine name. From the results of the visibility examination of a medicine name displayed on the commercial disinfectants currently used in our hospital, it became clear that the visibility of half of disinfectants was high, while the visibility of the remaining half was low.
