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The device for measurement
of photoelasticity of
transparent biological tissues
was developed for determination and visualization of
mechanical strength in the
eye cornea. The device
is a reflective
polariscope Nurnberger
type. Preliminary tests were held to measure the distribution of
internal strength
in the cornea with significant more then 3 В astigmatism before
and after correction. It was demonstrated that astigmatism is
not depend on anomalies of internal mechanical strength
distributions.
The dependencies of
biomechanical response of the eye cornea under
local ablation
by excimer laser radiation in paracentral zone from the
thickness of cornea was studied. Changes of optical power in the
centre of cornea at such treatment could be almost 10 times for
thin (440 mcm) and thick (650) corneas.
The influence of different
types of roughness of the
stromal part of the cornea
in the area of excimer
laser action using
LASIK (Fig.1) method
for the vision corrections on the quality of retinal vision was
investigated. The calculations show that under certain after
surgery treatments conditions it’s possible that significant
part of light energy was scattered on the roughness in the zone
of microkeratome and laser ablation action that decreases the
vision sharpness in the low contrast and scotopic conditions.
Theoretical and
experimental investigations of the
speckle structure
(Fig.2) that takes place under scattering of laser radiation on
the retina were done. The comparison analyze of efficiency
suppression of speckle
modulation by various
methods was presented.
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