Grossman L W, Faaland R W
Appl Opt. 1993 Jul 1;32(19):3497-503. doi: 10.1364/AO.32.003497.
We investigated the use of modulation transfer function (MTF) measurements to provide a standard test of minimum optical quality of intraocular lenses. We used a water cell with plane entrance and exit windows. This geometry is independent of lens material but relatively simple to implement. We investigated the choice of aperture stop, and 3.0 mm was deemed a suitable choice of stop diameter. Minimum acceptable performance must be specified if this technique is to be adopted as a standard method. The MTF of an ideal lens defocused 1/2 wave is suggested as a possible reference. Strehl ratios, although desirable because they can be measured directly without determining MTF's, were found to be unsuitable. These ratios tend to emphasize the high-frequency response, and the observed ratios are typically too low to provide assurance that the low-frequency response is as high as desired. MTF integrals or contrast at spatial frequencies of particular interest were found to be useful benchmarks of acceptable optical quality.
我们研究了使用调制传递函数（MTF）测量来提供人工晶状体最低光学质量的标准测试。我们使用了一个具有平面入射和出射窗口的水槽。这种几何结构与镜片材料无关，但实施起来相对简单。我们研究了孔径光阑的选择，3.0毫米被认为是合适的光阑直径选择。如果要采用这种技术作为标准方法，必须规定最低可接受性能。建议将理想镜片离焦1/2波长时的MTF作为可能的参考。斯特列尔比虽然很理想，因为可以直接测量而无需确定MTF，但发现并不合适。这些比值往往会强调高频响应，而且观察到的比值通常过低，无法确保低频响应达到所需的高度。发现MTF积分或特定感兴趣空间频率下的对比度是可接受光学质量的有用基准。
