Need Your Haag Streit BM-900 Repaired?

Tell us what’s wrong with your unit– we’ll arrange picking it up, and repair it back to factory specifications. Although your instrument may no longer be supported by the manufacturer, we produce a variety of original parts to ensure future service for the lifetime of your instrument.


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  • Use the turn screw (7) to set the chin rest (6) in such a way that the patient’s eyes are at the same height as the black mark (4) on the sides of the head rest.
  • Adjust the eyepieces (23) in accordance with the examiner’s refraction by turning the knurled rings and set the eye distance.
  • Switch on the illumination by turning the switch on the power supply.
  • Adjust the height of the slit lamp by turning the control lever (30) until the luminous aigrette is at eye level.
  • The rigid control lever (30) gently inclined towards the examiner can be used to push the entire instrument until the slit appears approximately focused on the cornea. This initial setting is verified with the naked eye. Fine tuning is performed by tilting the control lever, which is easily controlled at the top end, while observ- 6 ing via the stereo microscope (22).
  • The slit width is set left or right with the rotating knob (17), as is the angle be- tween the stereo microscope and illumination.
  • The slit image can be set vertically, horizontally or as diagonally as required by 7 turning the illumination facility on the control knob (20) (locking points at 45°, 90° and 135°; stops at 0° and 180°; scale in increments).
  • To ensure that unimpeded binocular fundus examination in the optical section is also possible at lateral angles of between 3° and 10°, a short mirror (12) is used, the illumination turned 90° using the locking screw (20) and tilted in 5° steps us- ing the latch (27), and the illumination and microscope turned to the central po- sition (0°).
  • The magnification of the stereo microscope can be changed on the slit lamp BM-900 by changing the lenses using the lever (24) or exchanging the eyepieces.
  • Front-lens glasses and contact glasses are used to examine the ocular fundus.

Diffuse illumination:

  • A diffuse illumination is achieved by positioning the diffusor (8) upstream. This enables overview monitoring and can be used for taking overview images with the Imaging Module. 

Indirect Illumination:

  • For observation in regredient light (indirect illumination), the centering screw (26) is loosened in order to move the slit image out of the center of the visual field. Tightening the screw centers the slit image again. 

Slit tilting: 

  • The latch (27) can be used to tilt the illumination in 5° steps. This creates an angled light beam during horizontal slit orientation. Tilting the slit enables re- flex-free examination with contact glasses (fundus and gonioscopy) and magni- fying glasses. 

  • Turning the diaphragm disc to the left stop switches on the fixation star and the ‘S’ symbol appears in the viewing window. In some examinations of the fundus, this star is projected onto the ocular fundus and is also visible to the patient, who is asked to focus on the center hole of the star. This shows the examiner the point where the patient’s vision is most focused. 
  • A typical use of the fixation star is close to the macula during laser treatment. The projection of the fixation star can also be used to identify microstrabismus. The fixation star is usually used with upstream red removal filter. 


The magnification of the microscope can be altered by changing the lens mounted in a revolving turret piece or by exchanging the eyepieces. Only the lever (48) is to be adjusted, from 1x to 1.6x, when changing the lens. In this instance, the examination need not be interrupted; nor is a new adjustment of the microscope needed. This change will alter the overall magnification from 10x to 16x (on the 10x eyepiece) and from 25x to 40x (on the 25x eyepiece) respectively.