Fig. 34. Modulation transfer function showing the effect of longitudinal chromatic aberration for myopic focus or overaccommodation of 0.5 D (left) and for hyperopic focus or underaccommodation of 0.5 D (right). Contrast (modulation) of the retinal image is highest for the wavelength in focus on the retina, and contrast is reduced for spectral components that focus behind and in front of the retina. As a consequence, relative contrast of spectral components distinguishes myopic from hyperopic focus. Calculations are for a 3-mm pupil with focus referenced to 550 nm light. |