A system (20) includes a radiation source (48) configured to emit beams (52) of radiation, one or more beam-directing elements (49) configured to direct the beams, a card (22) configured to undergo a change in appearance at sites on the card on which the beams impinge, a camera (54) configured to acquire one or more images of the card, and a controller (44). The controller is configured to process the images and to control the beam-directing elements, in response to processing the images, so as to direct the beams at one or more target points (74) in a field of view (72) of the camera, thereby causing the appearance of the card to change at one or more irradiated locations (76) on the card. Other embodiments are also described.

Wavefront measurements of eyes are often taken when the pupil is in a first configuration in an evaluation context. The results can be represented by a set of basis function coefficients. Prescriptive treatments are often applied in a treatment context, which is different from the evaluation context. Hence, the patient pupil can be in a different, second configuration, during treatment. Systems and methods are provided for determining a transformed set of basis function coefficients, based on a difference between the first and second configurations, which can be used to establish the vision treatment.

Wavefront measurements of eyes are often taken when the pupil is in a first configuration in an evaluation context. The results can be represented by a set of basis function coefficients. Prescriptive treatments are often applied in a treatment context, which is different from the evaluation context. Hence, the patient pupil can be in a different, second configuration, during treatment. Systems and methods are provided for determining a transformed set of basis function coefficients, based on a difference between the first and second configurations, which can be used to establish the vision treatment.