Abstract: A light-reactive thermal window is disclosed having external and internal panes. The external pane is composed of photochromic glass, while the internal pane is composed of clear glass. The panes are separated by a space having a uniform thickness. Each of the panes has a peripheral edge, with a spacer located between the peripheral edges of the external and internal panes. A sealant seals the peripheral edges of the external and internal panes. The window may include a frame securing together the spacer, the sealant, and the peripheral edges of the panes. Also disclosed is a method of preventing glare on a screen while minimizing climate control costs by installing a light-reactive thermal window near the screen.