Patent attributes
A stimulus light from a stimulus light source is projected to the retina of an ocular fundus under examination to stimulate the retina in localized fashion to generate a bioelectric signal from the retina. The stimulus light source is mounted on a movable block, and an operating lever is used to move the stimulus light source to change the stimulus light on the retina. The size of the stimulus light can also be varied using a panel having a plurality of openings with different diameters for allowing the stimulus light to pass through. This assures a reliable local ERG examination because the bioelectrical signal can be produced in a wider area of the retina. The operating lever is further fixed by inserting a cap to keep the projected stimulus light unchanged. This allows the burden on the examiner to be reduced remarkably, assuring a reliable local ERG examination.
