The slit lamp is an instrument used in eye care that provides an illuminated and magnified view of a patient's eye. The slit lamp typically includes a light projected through a slit to allow for observation of optical cross sections of the eye using an optical portion. The light is typically mounted on an articulated arm that is adjustable for observation of different portions of the eye. During examination, the patient's face is positioned against chin and forehead rests. While one eye is being examined by the optical portion, the patient is instructed to focus the other eye on a fixation light such that the examined eye is properly oriented. A small shield secures to the slit lamp and protects the examiner from coughs and sneezes, though in prior systems the shield is much too small to be effective.
In prior systems, the fixation light is a single light mounted on an arm that is attached to the portion of the slit lamp bearing the chin and forehead rests. The examiner is required to move the fixation light from one side of the slit lamp to the other when examining both eyes. When moving the optical portion from focusing on one eye to the other, the fixation light and its mounting arm tend to cause obstruction. Furthermore, since the fixation light is constantly being moved between eyes, the mechanisms enabling articulation of its mounting arm become worn, resulting in drift of the fixation light. In prior system the fixation light is positioned close to the patient's eye such that bumping of the light or its mounting arm can cause injury to the patient. The mounting arm is typically movable to a storage position to the side of the slit lamp. However, the fixation light and its mounting arm are still an obstacle to movement of the optical portion and the examiner's hand.
Further complications during examination of a patient using a slit lamp occur as the patient's face moves. It is typical for a patient to move the forehead away from the forehead rest. As a result, the examiner must “chase” the eye. As the patient moves away the eye also moves out of the range of focus of the slit lamp. As a result, the examiner typically must frequently remind the patient to stay forward against the forehead rest.
In view of the foregoing it would be an advancement in the art to provide a slit lamp facilitating the convenient non-obstructive positioning of a fixation light. It would be a further advancement in the art to provide a convenient means for maintaining a patient's forehead against a forehead rest during examination.