The primary cause of blindness in Japan is glaucoma. Glaucoma damages the optic nerve, leading to visual field loss or complete loss of vision. The person often fails to notice the problem in the early stage, and by the time they notice it, their visual field loss has already progressed significantly ( Figure 1).
Due to limitations of current medical science, it is often difficult to restore the damaged field of vision or eyesight.
The perimeters used in ophthalmology today impose a severe burden on patients; the patient must wear them on both eyes for 20 to 40 minutes and continue to gaze at a fixed point in a seated position while pressing a button whenever they observe light.
Therefore, we developed an inexpensive portable perimeter ( Figure 2), which consists of a portable, miniature, lightweight, and wearable display that emits perimeter lights to the person’s eyes, coupled with a sensor that automatically monitors the person’s gaze direction.