Design and analysis of an adaptive lens that mimics the performance of the crystalline lens in the human eye

Abstract

Tunable lenses are optical systems that have attracted much attention due to their potential applications in such areas like ophthalmology, machine vision, microscopy and laser processing. In recent years we have been working in the analysis and performance of a liquid-filled variable focal length lens, this is a lens that can modify its focal length by changing the amount of water within it. Nowadays we extend our study to a particular adaptive lens known as solid elastic lens (SEL) that it is formed by an elastic main body made of Polydimethylsiloxane (PDMS Sylgard 184). In this work, we present the design, simulation and analysis of an adaptive solid elastic lens that in principle imitates the accommodation process of the crystalline lens in the human eye. For this work, we have adopted the parameters of the schematic eye model developed in 1985 by Navarro et al.; this model represents the anatomy of the eye as close as possible to reality by predicting an acceptable and accurate quantity of spherical and chromatic aberrations without any shape fitting. An opto-mechanical analysis of the accommodation process of the adaptive lens is presented, by simulating a certain amount of radial force applied onto the SEL using the finite element method with the commercial software SolidWorks ® . We also present ray-trace diagrams of the simulated compression process of the adaptive lens using the commercial software OSLO ® .

Design and characterization of a tunable opto-mechatronic system to mimic the focusing and the regulation of illumination in the formation of images made by the human eye

“…b) Mechanism e RACTERIZA by the ciliary m der of the des he range of va was considered oth surfaces of applied radial f ee Figure 8b) [8] b).…”

“…In this direction, for the last years we have been working in the characterization of several optical systems which use different types of tunable lenses [5][6][7] and the physical-chemical properties of a polymeric material to build them; also, a PDMS-based (Polydimethylsiloxane, Sylgard 184) solid elastic lens (SEL) has been previously designed in order to mimic the performance of the crystalline lens of the human eye [8] which is used within a more complete optomechatronic system.…”

Polydimethylsiloxane crosslinking kinetics: A systematic study on Sylgard184 comparing rheological and thermal approaches

“…One of the most used PDMS is Sylgard184 (Dow Corning). It is commonly used in soft robots manufacturing or for the production of biomedical soft tissues, elastic lenses, and waveguides 6–14 that would benefit of a deeper knowledge of the crosslinking kinetics of their soft components. The crosslinking reaction of Sylgard184 takes place spontaneously at room temperature over approximately 48 h, but this time can be shortened by heating 15 .…”

Biomimetic models of the human eye, and their applications

“…Mechanical strain. One form of lens model proposed is based on the deformation of a polymeric lens through application of mechanical strain[61,65]. Liebetraut et al demonstrated this with the use of small servomotors acting on a polydimethylsiloxane (PDMS) lens (figure8(b)) to increase the focal length by 7.7% from an initial length of 32.5 mm under strain of around 10%.…”