A display screen magnifier is controllable by a user to magnify selected portions of a desktop including windows open on the screen. A moveable magnifier frame is provided, within which a magnified image is presented. The magnified image corresponds to screen content located within a magnification region underlying the magnifier frame, magnified to a set level of magnification. In one embodiment, the magnification region is moveable relative to the magnifier frame, in relation to movement of the magnifier frame on the display screen. Such relative movement can be used to avoid a potentially disorienting edge condition that arises when a magnifier frame reaches an edge of the display screen and stops, while its associated magnification region continues to pan. In another embodiment, the cursor of a user input device is moveable across the screen display into and out of the magnification region. When the position of the cursor falls within the magnification region, the cursor appears within the magnified image presented within the magnifier frame. A related feature avoids the potentially disconcerting effect of cursor disappearance as a pointing device cursor passes into a "lens shadow" defined between the magnification region and the magnifier frame.