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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 Â 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 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
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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