![]() Vertebrate eye lens growth occurs through a unique and ubiquitous mechanism (reviewed in ). It is not known whether such extrapolations are always appropriate for modelling human lens properties. Because of the difficulty in obtaining fresh human lenses, attempts are sometimes made to extrapolate from animal studies. However, such eyes have generally been stored for several days and their lenses may have become swollen during this time. Many of the required data can only be obtained in vitro, using lenses obtained from eye bank eyes. Comparison of 138 male and 64 female lenses indicated that there was no statistically significant difference between male and female lens weights in the linear (adult) growth mode.Ī thorough comprehension of the biochemical, biometric, optical and physical properties of the human lens, and how these change with age, is essential for understanding the functioning of the eye and the development of age-related visual disorders, such as presbyopia. ![]() The relationship of lens wet weight with age over the whole of the lifespan could best be described with the expression, W=1.38A b + 149exp^, where W is lens weight in mg, A b is postnatal age in years and A c is the time since conception in years. Soon after birth, growth becomes linear, dropping to 1.38 mg/year, and this rate is maintained throughout the rest of life. It was found that asymptotic growth during prenatal life and early childhood generates about 149 mg of tissue in a process, which can be modelled with a Gompertz function. ![]() Regression of age on log lens weight for the remaining 614 lenses indicated that, unlike other species, human lens growth appears to take place in two distinct phases. Variations in weights due to tissue handling procedures and the unavailability of statistical data for averaged sets precluded the use of >500 values in the present analysis. ![]()
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