Sometimes the doctor uses an instrument called an indirect ophthalmoscope, in which a binocular device is placed on the doctor’s head and a handheld lens is used in front of your eye to focus the image inside the eye. This method gives a three-dimensional view, allowing a better view of objects that have depth, including a detached retina or a swollen optic disk. It also allows a brighter light source to be used, which is important if the interior of the eye is cloudy, for instance due to infection or cataract. The indirect ophthalmoscope also allows a much wider field of view than a regular ophthalmoscope, so that the doctor can examine more of the retina at once.