Method for modifying the refractive index of ocular tissues and applications thereof

A method for modifying a refractive property of ocular tissue in an eye, comprising:

• determining a desired vision correction adjustment;
• determining a position, number, and design parameters of one or more optically modified gradient index (GRIN) layers to be created within the ocular tissue to provide the desired vision correction;
• writing the one or more determined GRIN layers by creating at least one GRIN layer in at least one of the corneal stroma and the crystalline lens having a gradient index of refraction in at least two directions that are generally transverse to a direction of light propagation through the ocular tissue by scanning a stream of laser pulses having a focal volume from a laser having a known average power along a line having a smoothly changing refractive index within the tissue;
• and
• varying one or more laser parameter including at least one of scan speed, laser average power, wavelength, and pulse width during the scan;
• and determining the varied one or more laser parameter as a function of a selected gradient index of refraction along a scan line;
• and
• further comprising creating at least two optically-modified GRIN layers having an interlayer spacing, S, equal to or greater than five μm.