A five-group zoom lens is formed of, in order from the enlarging side of the zoom lens, a negative first lens group that is movable for focusing and that is stationary during zooming, a positive second lens group, a positive third lens group, a negative fourth lens group, and a positive fifth lens group that is stationary during zooming. The syringe shield may reduce a healthcare provider’s exposure to radiation andor may reduce or eliminate ambient light contamination to optically sensitive components in the syringe. Nut drop begins about October 10 and continues for a 5-6 week period. In response to any of the mouse and keyboard strokes matching the toggle input, the over-shoulder status is automatically toggled, whereby the over-shoulder status is updated in a contact list of at least one other IM client, such that activation of the over-shoulder status serves as a warning that the user has a visitor.