👁 Shack-Hartmann Eye Aberrometer (2D): Zernike Wavefront, Lenslet Spot Shifts, Refraction and Retinal Image

A 2D Shack-Hartmann eye aberrometer lab: Zernike wavefront with defocus, astigmatism, coma, trefoil and spherical aberration, lenslet spot shifts with dynamic-range limits, noisy modal reconstruction, sphere/cylinder refraction, Strehl ratio, FFT point-spread function and a blurred letter, with eight numerical checks.