Research On The Establishment And Printing Of Oriental Lens Model

Aiming at the individual differences of human eye,it is important to establish a lens optical model that is consistent to eastern human eye data and implement the corresponding digital processing technology.3D printing technology can be personalized and manufactured according to the three-dimensional digital model of the lens,which can not only solve the problem of restoration,but also improve the quality of human eye imaging.The optical design software Zemax is used to inversely obtain the unknown parameters of the intraocular lens to construct an optical model of the human eye lens.The 3D printing technology of the three-dimensional solid lens model is studied and its effects are evaluated.The key optical models of eye model include the front and back of cornea and lens model with biconic surface.Based on the basic data of the eastern human eye model published by the mentor group in the early stage,taking its inherent aberration as the reference value.While keeping the length of the eye axis constant,according to the layered 3D printing technology,the lens is sliced layered in the axial direction.The impact on human eye imaging quality about layering method and accuracy is studied,a continuous gradient index lens model discrete expression model about layer thickness and refractive index layering accuracy is established.When layer thickness is less than 0.1 mm,the refractive index layering accuracy is less than 0.01,the imaging quality of the discretized lens model and the continuous gradient model is almost no difference.This article analyzes the current widely use of 3D printing technology and 3D printing materials.Finally SLA printing technology,photosensitive resin for the material is chosen to print a single refractive index lens model,and FDM printing technology,PMMA and PLA for the materials is chosen to print a three-layer refractive index lens model.Combining the key optical model of human eye and the materials used for printing the lens model,based on the eastern human eye optical model,three kinds of lens models are designed.A human eye model with single refractive index of 1 mm thick made of photosensitive resin material has an image plane diffuse spot RMS radius of 1.474 ?m and 4 mm thick made of photosensitive resin material has an image plane diffuse spot RMS radius of 0.698 ?m.The optical model of the human eye with a three-layer refractive index lens and a lens thickness of 1 mm has an RMS radius of the image surface diffuse spot of 1.978 ?m.3D printers are used to obtain three-dimensional lens samples.The three-dimensional lens sample obtained by the FDM printing process has a serious step effect and does not meet the optical transmission requirements of the intraocular lens but the lens sample obtained by the SLA printing process has good light transmittance.By setting up experimental detection devices,the stress,focal length and surface quality of the two lens samples printed by the SLA technology are tested.Stress analysis are performed on the 1 mm and 4 mm thick three-dimensional lens samples made of photosensitive resin,and it is found that both stresses exist and birefringence occur.The focal length in the air of the 1 mm lens sample obtained by measurement is 15.44 mm,which is 4.98% different from the theory.The focal length in the air of the 4 mm lens sample obtained is 12.80 mm,which is 5.81% different from the theory.Veeco white light interferometer is used to measure the surface shape and roughness of the two lens samples.The deviation of the profile is about 120 nm,and the curvature radius of the back surface of the lens did not change much.The accumulation in the middle causes the curvature radius of the front surface of the lens to become smaller.The results show that lens sample obtained by the FDM printing process has a serious step effect.The lens sample obtained by the SLA printing process has stress and the refractive power is within the range of use of the lens,but the surface micro-morphology is poor.