This document provides an operator's manual for the VISIONlite application software used to control Thermo Scientific UV/Vis and Vis spectrophotometers. The software includes four application modules (Scan, Rate, Fixed, Quant) for recording and evaluating spectral data from compatible instruments. It describes installation requirements, basic operation and navigation of the software interface, and parameters and functions specific to each application module. Safety information is also provided regarding proper use and interpretation of results from the software.