Pointer J S
Ophthalmic Physiol Opt. 1995 Jul;15(4):241-8.
New transverse clinical data are presented which confirm and extend earlier results to be found in the literature describing the time course of presbyopia-as indicated by the magnitude of the binocular spectacle add--in normally sighted male and and female Caucasian subjects. An initial steep increase in add requirement beginning in the early forties becomes relatively slower but still of significance beyond the mid-fifties. This observation is correlated with the age-related progressive decline in the amplitude of accommodation, itself a consequence of physiological changes in the crystalline lens and capsule. The continuing need for an increase, albeit at a reduced rate, in the positive near supplement beyond the mid-to-late fifties-by which time little or no useful accommodation is available-is now attributed to the visually disruptive effects within the high spatial frequency domain of progressive age-related lenticular changes. The magnification afforded by the positive add increases spatial grain and thereby enhances visibility of detail in an ageing visual system free of any gross senile visual pathology. A small but consistent gender difference is revealed in presbyopic corrections: physiological and physical bases are suggested for the observation that females require an add of greater magnitude than their age-matched male counterparts.
本文给出了新的横向临床数据，这些数据证实并拓展了早期文献中的研究结果，这些结果描述了正常视力的白种男性和女性老花眼的时间进程（以双眼眼镜附加度数的大小表示）。从四十岁出头开始，附加度数需求最初急剧增加，到五十多岁中期后增速相对变缓，但仍具有显著意义。这一观察结果与年龄相关的调节幅度逐渐下降有关，而调节幅度下降本身是晶状体和晶状体囊生理变化的结果。五十多岁中后期之后，尽管增加幅度变小，但仍持续需要增加正性近附加度数（此时几乎没有或没有可用的有效调节），现在认为这是由于与年龄相关的晶状体渐进性变化在高空间频率域内产生的视觉干扰效应。正性附加度数提供的放大作用增加了空间颗粒度，从而提高了没有明显老年性视觉病变的老化视觉系统中细节的可见度。老花眼矫正中发现了一个虽小但一致的性别差异：对于女性比同龄男性需要更大附加度数这一观察结果，提出了生理和物理方面的依据。
