The present invention projects a projection image of appropriate brightness on an eye of a test subject even when an observed image of relatively high brightness is acquired. An observation device (1) is provided with a projection means (110) capable of projecting on an eye of a test subject a first image to be projected on the corneal surface of the eye and a second image to be formed on the retina of the eye, and an image pickup means (140) for acquiring an observed image by capturing an image of the eye. The projection means uses the observed image as the second image and adjusts the projection brightness, which is the brightness of the first image and/or the second image that the projection means is to project, on the basis of the observed brightness, which is the brightness of the observed image.
