An optical module (10) comprises a positive meniscus lens (16) having a focal length F1 and comprising a first convex optical surface (12) and a second concave optical surface (20), and a plano-convex lens (22) having a focal length F1 and comprising a third flat optical surface (24) and a fourth convex optical surface (26) from an object side (12) to an image side (14). The curvatures of the four optical surfaces (12, 20, 24, 26) are defined by the equation: Zi=CURViYi2/(1+(1+Ki)CURVi2Yi2)½)+(Ai)Yi2+(Bi)Yi4+(Ci)Yi6+(Di)Yi8, and the two lenses are defined by 0.35