Abstract: A binocular indirect opthalmoscope has a light source for producing an illumination beam and an illumination mirror (7) for directing the illumination beam to an eye to be viewed. The opthalmoscope also has, viewing optics including left-hand and right-hand eyepieces (12,13) and an optical splitter (9,10) for directing light along left-hand and right-hand viewing paths to the two eyepieces. An aperture holder (20) is pivotally mounted in a frame (3,5,6) of the opthalmoscope and adjusts the size of the illumination beam, under the control of a manually rotatable control knob (24). The movement of the aperture holder is transmitted, by means of mechanical linkage, to a moveable carriage (15) on which is mounted both the optical splitter and the illumination mirror, so that when the user moves the control knob to adjust the size of the illumination beam the optical splitter and the illumination mirror are also adjusted in position with respect to the opthalmoscope frame.

Abstract: A binocular indirect opthalmoscope has a light source for producing an illumination beam and an illumination mirror (7) for directing the illumination beam to an eye to be viewed. The opthalmoscope also has, viewing optics including left-hand and right-hand eyepieces (12,13) and an optical splitter (9,10) for directing light along left-hand and right-hand viewing paths to the two eyepieces. An aperture holder (20) is pivotally mounted in a frame (3,5,6) of the opthalmoscope and adjusts the size of the illumination beam, under the control of a manually rotatable control knob (24). The movement of the aperture holder is transmitted, by means of mechanical linkage, to a moveable carriage (15) on which is mounted both the optical splitter and the illumination mirror, so that when the user moves the control knob to adjust the size of the illumination beam the optical splitter and the illumination mirror are also adjusted in position with respect to the opthalmoscope frame.

Abstract: An ophthalmoscope has illuminating optics (10) for projecting a beam of light into an eye under examination and imaging optics (14) for creating an image of said eye for viewing by a user. The imaging optics comprises an objective lens system (16) and an eye piece lens system (20). Two corneal reflex stops (138 and 148) are positioned one on either side of the corneal image formed by the objective lens system. The stops block reflections from the cornea of the eye under examination over a range of distances of the ophthalmoscope from the eye. The use of the two corneal reflex stops results in the precise positioning of the ophthalmoscope relative to the eye under examination not being critical to the blocking of the corneal reflex.

Abstract: A puff tonometer includes two light sources located at diametrically opposite points, preferably equidistant from the optical axis of the objective lens assembly of the tonometer. The sources are arranged to direct light forwardly of the tonometer such that, in use, and when positioned close to a patient's eye under test, light from the two sources, after reflection by the anterior corneal surface of the eye under test, will be imaged by the objective lens assembly of the tonometer, to appear as two small areas of light in the field of view.

Abstract: A puff tonometer which includes an object at a point in the optical path of light from a source of light in the tonometer, typically near to the source, such that an in-focus image of the object will be formed in the user's field of view when the tonometer is at the critical distance from an eye under test at which the automatic air pulse generating means will be triggered by light reflected from the eye forming an in focus image of a mask on a plurality of photoelectric sensors. A second object may be located in the same region of the tonometer as the first object, but in a plane which is spaced from the plane containing the first object, whereby its image will come into focus in the field of view just before the image of the first object comes into focus, as the unit is moved slowly towards the patient's eye.

Abstract: A streak retinoscope projects an elongate patch of light onto the retina of an eye under examination. A housing (1) contains means for rotating the patch relative to the eye and adjustable focusing means for focusing the patch on the eye. Both the rotation means and the focusing means are adjusted by a single control member, such as sleeve (62), which encircles at least part of the housing member. The control member is coupled at least to the rotation means (and preferably also to the focusing means) by a magnetic linkage so as to permit rotation of the control member on the housing through at least one full revolution.

Abstract: An ophthalmoscope has viewing optics through which, in use, the user views an eye under examination. Those optics include one or more light receiving elements (62 and 64). The ophthalmoscope also has a centrally positioned camera (14) for detecting an image corresponding to that seen by the user. Light is reflected into the camera objective by means of a reflector (16) which is also centrally positioned on the ophthalmoscope and is situated in substantially the same plane as said elements of the viewing optics, but is laterally spaced therefrom. The central positioning of the camera does not adversely affect the lateral weight distribution of the ophthalmoscope, whilst the provision of a reflector at the same level as the optical elements helps to preserve the congruents between the image detected by the camera and that seen by the user if the condenser lens (used to form the virtual image of the eye under examination) is moved towards or away from the ophthalmoscope.

Abstract: An indirect ophthalmoscope is equipped with a camera (14) to enable the view seen by the user of the ophthalmoscope to be displayed. Light is reflected into the camera by a reflector such as a prism (16) which is preferably substantially co-planar with the ophthalmoscope's optical elements (through which the user sees an eye under examination). The prism (16) and camera (14) are centrally mounted on the ophthalmoscope through mounting means, such as a frame, which has adjustment means for adjusting the positions of the prism and camera relative to the ophthalmoscope so as to alter the position of the field of view of the camera relative to the ophthalmoscope's optical elements. The adjustment means help to ensure that the field of view of the camera, and hence the displayed image, corresponds to the view seen by the user of the ophthalmoscope. The camera, prism and frame may form part of an attachment which may be retrofitted to an existing ophthalmoscope.