Essilor Medica 700, User Manual

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Wave Analyzer Medica 700 User Guide
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Overview of the Software
LOA : Shows the values of the lower order aberrations, total LOA, tilt, defocus and astigmatism.
HOA : Shows the values of the common higher order aberrations, total HOA, trefoil, coma,
tetrafoil, fourth order astigmatism, spherical aberration, pentafoil, fifth order trefoil and fifth order
coma.
Aberrations values and maps can be shown in OPD (optical Path Difference) mode or in WFE
(WaveFront Error) mode, as defined in the settings screen (See the General subtab under the
results tab of the settings screen )
The Optical Path Difference (OPD) is defined as the difference between the aberrated and
the ideal unaberrated wavefronts. The OPD is positive if the aberrated wavefront leads the ideal
unaberrated wavefront.
Also, if the aberrated wavefront curves in more than the unaberrated wavefront, the OPD is
positive. Therefore, a negative focal shift will introduce a positive aberration.
The WaveFront Error (WFE) is defined as the difference between the ideal unaberrated
wavefronts and the aberrated wavefronts. Essentially, WFE represents the required correction
for achieving unaberrated vision.
OPD and WFE modes relate in the following way:
OPD(x,y)= -WFE(x,y)
The chosen mode is marked on the left side of the coefficient chart above the table.