Phase modulators for refractive corrections of human eyes

Using optical modeling, it is shown that it is possible to construct a pixilated spatial light modulator, SLM, to provide a dynamic correction for the loss of accommodation in most adults over the age of 55. The optical correction for this loss, known as presbyopia, is modeled by placing a pixilated SLM with a spherical optical path difference profile at the apex of the front surface of the eye. It is shown that an 8x8 mm(2) SLM divided into 127x127 pixels and capable of 20 waves of phase retardation (OPD depth) at 550nm provides up to 2D of accommodation for pupils of 6mm in diameter while providing optical quality equivalent to the natural state of the eye. The required OPD depth may be reduce to 15 waves if the correction is required over a smaller 5mm pupil. It is also shown that the poor image quality resulting from small array sizes (9x9 or 21x21 pixels) is due to the complex diffraction and interference effects resulting from the structure of the array and the circular pupil.