Shear modulus data for the human lens determined from a spinning lens test.
Bottom Line: The results from these supplementary tests are in good agreement with the data obtained from the principal 1,000 rpm tests.Studies on the possible effects of lens drying during the test suggested that this factor is unlikely to have led to significant errors in the experimental determination of the shear modulus.This comparison highlights various limitations and inconsistencies in the data sets.
Affiliation: Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.Show MeSH
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Mentions: The optimum computed stiffness profiles for each of the three forms of SVF for the three representative lenses are shown in Fig. 6; the relevant shear modulus parameters are given in Table 2. In these plots the step stiffness change in Model D is plotted at the mean relative position of the transition from the nucleus to the cortex. For the 33-year lens the two non-homogeneous models indicate that the nucleus is less stiff than the cortex. This situation is reversed for the 50-year lens, for which the nucleus is stiffer than the cortex. The 43-year lens provides an interesting example of the intermediate case where the lens is approximately homogeneous (i.e. the nucleus and cortex have similar values of shear modulus). In all cases, as expected, the Model H data are intermediate between the extreme values of both Models D and E.
Affiliation: Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.