This study examines usual postures of the elderly when applying eye drops, as well as the relationship between the use of the backrest of a chair and the success in application. A survey of elderly people was conducted regarding their postures where elderly women applied the eye drops. A motion analysis of the involved movements was then carried out. From videos, angles of the neck extension, the elbow joint, the lumbar extension, and that of the eye drop container were measured, all during application. Comparisons were made between the presence and the absence of the backrest of a chair, the success, and the failure in application, and whether the drops missed their intended mark. It was found that when the application failed in the absence of the backrest, the neck extension angle was significantly narrower. However, when using the backrest, an extended waist led to easier neck extension, suggesting that the risks of application failure or the dropper tip touching the person could be reduced. It can be concluded that using a chair with a backrest makes applying eye drops safer and easier, and this method can be incorporated into the instructions regarding the application of eye drops.