Objective 1 Flashcards
The words slit lamp and biomicroscope are often used interchangeably to identify one instrument. The slit lamp is the source of the light beam that can be widened or narrowed both horizontally and vertically as needed, while the biomicroscope is the binocular microscope that has its focus set at the same place or plane as the slit lamp’s beam. This makes the two parts of the instrument parfocal.
True or False?
True
Taking the slit beam out of ………….., separates the focal points of the two systems for some illuminations.
Click Stop
On most models, the slit beam width controls allow the examiner to adjust the beam width from…….
0.1mm to 14mm
The vertical height of a slit can be adjusted in order to focus on …..
a small, specific part of the eye.
The circle can be made very small if desired, especially for the conic section. This helps the examiner see….
aqueous flare
Low magnification is for
general observations
Medium Magnification is for
Structures
High magnification is for
detail magnification
The cobalt-blue filter is used for
fluorescein testing
The red free filter is used for
viewing blood vessels and contact lenses, but its primary use is for fundus observations with a 70D lens.
The heat-absorbing filter is used for
diffuse illumination to increase patient comfort
the polarizing filter is to
reduce glare on a 70D lens and for cataract detection.
There are click-stop settings that provide the examiner with a
reference point from which to start an exam
The points at which the scope and the lamp both aim in the same direction is called
in click-stop
Any point where the lamp and scope aim at different spots is called
out of click-stop.
Used for moving the scope and the beam together laterally to observe different areas of the eye. It is moved forward and backward for focusing
Joy-stick
This part of the assembly can be moved up and down to center the patient’s eyes with the scope.
Chin rest
This helps the patient’s head to be held steady. This is crucial especially for high magnification, with its inherently poor depth of focus and intensity of the light
Head rest
These controls are knobs or levers that vary with different instruments.
Slit Width & Height Controls
These controls are levers or click dials, and some are zooms such as those seen on video cameras. A zoom control is a smooth increase in magnification as opposed to the abrupt 6X to 40X of the lever or click dial type devices.
magnification controls
This is a metal rod, which is placed in the hole at the base of the front of the assembly. It is used to help the examiner make sure the slit and the scope are focused at the same distance, or parfocal. It is then removed. Periodic checks of the binocular focus should be done.
Focusing Rod
