Provided is an apparatus for performing ophthalmic surgery that comprises aneyecontact element having a small wavefront error. The apparatus comprises alight sourceconfigured to generate a light beam having a wavelength between 300 nm and1900 nm.A focusing lens is provided in optical communication with the light source,the focusinglens configured to focus the light beam into a focused light beam. The contactelement isconfigured to contact an eye to be treated, and comprises a polymer and has atransmission ratio of at least 90% relative to the focused light beam and thatisconfigured to introduce a wavefront error of at most about .lambda./2 to thefocused light beamwhen the focused light beam passes through the contact element. The focusinglens isconfigured such that the focused light beam has a region of focus within acornea of theeye, the region of focus having a diameter of 15µm or less. Optical meansis providedthat is configured to direct the focused light beam having a region of focuswith adiameter of 15µm or less repeatedly and successively over a treatmentregion within thecornea of the eye to form an incision in the cornea. The contact elementcomprises amaterial having an index of refraction in the range of 1.500 to 1.550 relativeto thefocused light beam.
