An apparatus and method may provide uniform illumination on the retina using scanned continuous wave laser sources by making use of waveguides with regular shaped cross sections. Some embodiments of the present invention may provide illumination uniformity for selected spots and/or whole target scans, and may provide for constant dwell times every point of the scanned beam. Furthermore, the non-uniformities caused by starting and stopping scans may be eliminated by, for example, clipping-off both the beginning and end of the scan with a hard aperture. A modulator may be provided, enabling uniform irradiation of selected target areas.