NOVELTY - A light-reactive thermal window for homes and other buildings comprises an external pane (12) with photochromic glass and an internal pane (14) having clear glass.    USE - The invention is used for homes and other buildings. It is also useful for windows having attractive views.    ADVANTAGE - The invention provides better glare control and is more convenient than other glare-control methods. It is also energy efficient and since the internal pane of glass is clear, heat does not build up in the space between the internal and external panes, thus increasing energy efficiency and preventing damage to the window. It selectively controls the entry of visible light on an as-needed basis. The combination allows large windows to be included in homes and offices in hot climates, without requiring view-obscuring curtains and blinds. No complicated electrical systems or fluid pumping systems are necessary to adjust the tint of the glass. The invention also minimizes air conditioning and heating cost.    DETAILED DESCRIPTION - A light-reactive thermal window comprises 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 (22) having uniform thickness. Each of the panes has a peripheral edge (16), with a spacer (28) located between the peripheral edges of the panes. A sealant (30) seals the peripheral edges of the panes. An INDEPENDENT CLAIM is also included for a method of preventing glare on screen while minimizing climate control costs comprising (i) selecting a thermal window of the above invention; (ii) selecting a window opening which is located near a screen; and (iii) installing a thermal window in the window opening. The outer and inner panes are located adjacent to external and internal (26) environments, respectively.    DESCRIPTION OF DRAWING(S) - The figure shows a fragmented, cross-sectional view of the peripheral edge of a window.    External and internal panes (12, 14)    Peripheral edge (16)    Space (22)    Internal environment (26)    Spacer (28)    Sealant (30)    Frame (32)