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Instruction Manual Easygraph
7.5.4 Changing Settings
The examination program allows the user to adapt
working procedures to his own preferences. This is
carried out in the
"Change Settings"
menu.
The following points can be adjusted:
•
Display units
The measured curvature of the cornea can be
given either as the radius of curvature in mm or
as the equivalent of curvature in diopters. The
conversion is carried out according to the
following formula:
(
)
r
D
mm
D
•
−
=
1
3375
,
1
•
Color scale stepping:
Different formats are possible for the color scale.
The scale can be absolute or relative. When the
scale is absolute, each radius of curvature always
has the same color. A relative color scale is
automatically scaled; the center of the scale
corresponds to the mean curvature of the corneal
surface.
The relative color scales can be displayed in
three different increments (cf. table below).
Relative
Unit of Curvature
Diopter
Millimeter
Fine
0.25 D
0.05 mm
Medium
0.5 D
0.10 mm
Coarse
1.0 D
0.20 mm
The absolute color bar has a resolution of 0.10
mm in the central area. The increment is 0.2 mm
below 6.6 mm, and 3 mm above 10.5 mm.
The diopter is selected as the unit of curvature,
the curvature values are converted into diopters,
but the colors on the absolute color scale do not
change.