A system for measuring the optical characteristics of a curved glass sheet, the glass sheet having a first dimension and a second dimension, wherein the glass sheet is curved at least about one or more axes of curvature which are generally parallel to the first dimension, the apparatus comprising: a conveyor for conveying the glass sheet in a first direction generally parallel to the first dimension of the glass sheet; at least two displays, each display projecting a preselected contrasting pattern; at least two cameras (28-40; 82); and a programmable control including at least one computer, which includes at least one processor programmed to execute logic for controlling each of the cameras (28-40; 82) to acquire at least one image of the reflected pattern of the associated display on the glass sheet as the glass sheet is conveyed across the path of the projected pattern in the first direction, logic for analyzing and combining the data acquired by the cameras (28-40; 82) to construct three-dimensional surface data representative of the shape of the surface of the glass sheet, and logic for analyzing the data representative of the surface of the glass sheet to determine optical characteristics of the glass sheet; characterized in that each one of the at least two cameras (28-40; 82) is uniquely paired with one of the displays, wherein each display and camera pair are mounted in a spaced-apart relationship a known distance and angle from the surface of the glass sheet such that the camera detects the reflected image of the pattern projected on the surface of the glass sheet from its associated display, and wherein each of the display and camera pairs are spaced apart from each other at least in a second direction across the second dimension of the glass sheet such that each camera detects the reflected image of the pattern projected on the surface of the glass sheet from only its associated display, and wherein the patterns detected by the cameras (28-40; 82) together cover the entire surface in the direction of the second dimension of the glass sheet. a conveyor for conveying the glass sheet in a first direction generally parallel to the first dimension of the glass sheet; at least two displays, each display projecting a preselected contrasting pattern; at least two cameras (28-40; 82); and a programmable control including at least one computer, which includes at least one processor programmed to execute logic for controlling each of the cameras (28-40; 82) to acquire at least one image of the reflected pattern of the associated display on the glass sheet as the glass sheet is conveyed across the path of the projected pattern in the first direction, logic for analyzing and combining the data acquired by the cameras (28-40; 82) to construct three-dimensional surface data representative of the shape of the surface of the glass sheet, and logic for analyzing the data representative of the surface of the glass sheet to determine optical characteristics of the glass sheet; characterized in that each one of the at least two cameras (28-40; 82) is uniquely paired with one of the displays, wherein each display and camera pair are mounted in a spaced-apart relationship a known distance and angle from the surface of the glass sheet such that the camera detects the reflected image of the pattern projected on the surface of the glass sheet from its associated display, and wherein each of the display and camera pairs are spaced apart from each other at least in a second direction across the second dimension of the glass sheet such that each camera detects the reflected image of the pattern projected on the surface of the glass sheet from only its associated display, and wherein the patterns detected by the cameras (28-40; 82) together cover the entire surface in the direction of the second dimension of the glass sheet.