A television cathode ray tube has associated therewith a power supply for developing discrete supply voltages. A general purpose electron gun is depicted for receiving supply voltages from the power supply to produce a sharply focused beam of electrons at the cathode ray tube screen. The gun comprises associated cathode means and grid means for producing a beam of electrons, and novel focus lens means. The focus lens means receives electrons from the cathode means and a predetermined pattern of voltages from the power supply and comprises at least three electrodes for establishing a single, continuous electrostatic focusing field characterized by having an axial potential distribution which, at all times during tube operation, decreases smoothly and monotonically from a relatively intermediate potential to a relatively low potential spatially located at a lens intermediate position, and then increases smoothly, directly and monotonically from said relatively low potential to a relatively high potential.