METHODS OF ALTERING THE REFRACTIVE INDEX OF MATERIALS

摘要

Methods and devices for altering the power of a lens, such as an intraocular lens, are disclosed. In one method, the lens comprises a single polymer matrix containing crosslinkable pendant groups, wherein the polymer matrix increases in volume when crosslinked. The lens does not contain free monomer. Upon exposure to ultraviolet radiation, crosslinking causes the exposed portion of the lens to increase in volume, causing an increase in the refractive index. In another method, the lens comprises a polymer matrix containing photobleachable chromophores. Upon exposure to ultraviolet radiation, photobleaching causes a decrease in refractive index in the exposed portion without any change in lens thickness. These methods avoid the need to wait for diffusion to occur to change the lens shape and avoid the need for a second exposure to radiation to lock in the changes to the lens.

主权项

1. A method of altering the optical power of a lens, comprising:
providing a lens comprising:
a polymer matrix having photobleachable chromophores; anda photosensitive donor lacking photoinitiating groups and responsive to a first selective wavelength of energy for generating primary excited state donor molecules which are not responsive to said first selective wavelength, but are responsive to sequentially applied second selective wavelengths of energy for generating secondary higher energy level excited state donor molecules;the chromophores having a lowest primary excited state greater than the primary excited state of the photosensitive donor, the secondary higher energy level excited state of the photosensitive donor molecules being greater than the lowest primary excited state of the chromophores; and exposing a portion of the lens to radiation at the first selective wavelength to generate primary excited state donor molecules; and exposing the exposed portion of the lens to radiation of the second selective wavelength to generate secondary higher energy level excited state donor molecules, causing photobleaching to occur in the exposed portion of the lens and changing the refractive index of the exposed portion of the lens, thereby altering the optical power of the lens.