Study On The Characteristic Of The Wave-front Aberrations Of Human Eye Based On Eye Model

This article focus on wavefront aberration characteristics and visual correction of thehuman eye model to the make the following research: first brief overview of thedevelopment of the human eye aberration and eye model; then introduced the physiologicalstructure of the human eye, the concepts and mathematical representation of the human eyeaberration; After that based on the model of the human eye, respectively studied the impactof pupil diameter, field of view angle, color and visual axis, the axis adjustment on thewavefront aberrations and image quality; Finally, according to the current wave differencestudy on the disunion of measuring surface and corrected surface.After the use of optical design software zemax create Gullstrand-Le Grand eye model(G-eye model) and Liou eye model (L-eye model), this paper studied the impact of changesin pupil diameter on the human eye model wavefront aberration characteristics and imagequality. Along with the increase of the pupil diameter, for defocus amount, two eye modelsshowed the trend of increasing significantly after the first stable. The spherical aberrationof the two eye model have gradually increasing trend, but the spherical aberration of theL-eye model changes in amplitude slightly less than the G-eye model. Wavefront PV valueof the two eye models showed a gradual upward trend, but the PV value of the G-eyemodel wavefront aberration is greater than L-eye model; the two eye model changes andwavefront aberration PV value is roughly the same for the rms value of the wavefrontaberration. The impact of pupil diameter on the imaging quality of the human eye is thatwith the gradually increase of the pupil diameters, the two type of image quality bothshowed a trend of increased and then decreased.After the establishment of the G-eye model and L-eye model, studied the impact ofchanges the field of view on the human eye model wavefront aberration characteristics andimage quality. With the gradual increase in the field of view, the L-eye model is smooth inchanges in defocus amount, the maximum difference value is less than0.7. The changeamplitude of the defocus amount of G-eye model is much bigger than L-eye model. Andwith the increase of the view angle, the amplification is growing increasingly. As for thewavefront PV value, with the gradual increase in the field of view L-eye model showing slow and steady rise, but G-eye model showing large fluctuations in the upward change.For the rms value of the wavefront aberration, in the case of the gradually increase of fieldof view, both eye model increased gradually, but L-eye model showing slow and steadyrise, G-eye model showing large fluctuations in the upward change.In this point the rise ofthe eye model rms value is consistent to the actual measured change. With the gradualincrease of the angle of vision, the image quality of the eye models showed varying degreesof reduction. When the field of view angle is0°the image quality of the two eye models areoptimal.After the establishment of the G-eye model and L-eye model, studied the impact ofchromatic aberration on the human eye model wavefront aberration characteristics andimage quality. Along with the increase of incidence wavelength, the change trend ofdefocus amount of L-eye model is increasing gradually, but that of G-eye model isdecreasing gradually. Compared with the actual human eye, L-eye model is more in linewith the actual variation of human eye. Along with the increase of incident wavelength，thetendency of spherical aberration curve of L-eye mode increasing, but the tendency ofspherical aberration curve of G-eye mode increasing decrease gradually, although thesetendencies of spherical aberration is different, the of change is very small; The wavefrontaberration PV value of two kinds of eye model firstly rises and declines again, but theposition of the turning point of L-eye model is bigger than the position of the turning pointof G-eye model; The tendency of wavefront aberration rms value and PV value of twokinds of eye model is similar, firstly rising and declining again, the position of the turningpoint of L-eye model is bigger than the position of the turning point of G-eye model; Alongwith the increase of incidence wavelength, image quality of two eyes model firstly risesand declines again, when incidence wavelength for450and500nm, image quality of twoeyes model is good, it also demonstrates that the two kinds of eye model responses theactual response characteristics of the human eye.Using the optical design software zemax establishes the Schematic eye model, toadjust the angle of the eye model on optical axis and optical axis outside,along with the increaseof diopter, spherical aberration sends down gradually; The change of human eye coma aberration rises,but the rangeability change slowly; the aberration RMS value firstly rises anddeclines again along with the increase of diopter, and, aberration RMS value increases withthe increase of angle of field of view; The human eye aberration PV value firstly rises anddeclines again with with the increase of diopter, aberration PV value increases with theincrease of angle of field of view; When the angle of view filed is small, the change of MTFcurve of wavefront aberration is similar, firstly declining and rising again, When theangle of view filed is big, the mage quality of two eyes increases, the change is not verygreat. And with the increase of the angle of view filed, the human eye image quality isimproved.Finally the Hartmann-Shack human eye wave aberration gauge is used to measure20times, and its average and RMS values is recorded, on this basis, the front35term ofhuman eye wavefront aberration is substituted Zernike polynomials, and the wavefrontaberration Zernike of measuring plane is got, the wavefront aberration of pupil plane iscalculated,and the results are showed by3D stereogram, After average value of human eyewavefront aberration is got，the2,4order Zernike coefficient of human eye wavefrontaberration is substituted Zernike polynomials，using the theory of angular spectrummethod，after solution package，the wavefront aberration of pupil plane is converted to thewavefront aberration of correction plane，and3D stereogram of the wavefront aberration ofcorrection plane is got. This method can decrease the error of human eye because of the locationwhich is not unified of measurement plane and correction plane.