An ultraviolet telescope is a telescope that examines the ultraviolet portion of the electromagnetic spectrum between visible light and X-rays. It usually uses reflectors instead of lenses to keep glass out of the light path, and must be located at high altitudes or in space to view UV light. An ultraviolet telescope has a detector array sensitive to UV light and functions similarly to other telescopes, but is designed to observe the ultraviolet portion of the spectrum. Examples of UV telescopes include the IUE, EUVE, Hubble Space Telescope, FUSE, and UIT.