A gradient inspection system (200, 400, 500, 600, 800) for optical inspection of a transparent and/or specular object, the system being constructed and configured to analyse a wavefront transmitted through and/or reflected off the object (208,410,520, 610, 812), the system comprising: a. an illumination system (204, 404, 504, 615, 740) constructed and configured to illuminate said object such that each point of said object receives a similar angular distribution of light; b. an imaging system (212, 414, 542, 602, 702, 802) constructed and configured to image said object onto an image plane; c. at least one aperture stop (214, 420, 514, 604, 708, 804) of said imaging system; d. a gradient element (202, 402, 502, 606, 808, 1204, 1206, 1208) comprising at least two distinct areas, each area enabling a passage of light of at least one of a defined gradient feature being a measurable characteristics, therethrough, selected from spectrum and power, said gradient element being disposed in at least one of said at least one aperture stops of said imaging system; e. a sensor (216, 422, 546, 612, 706, 830) disposed in said image plane of said imaging system, said sensor being capable of differentiating between said at least two distinct areas of said gradient element (202, 402, 502, 606, 808); and said sensor (216,446, 546, 612, 620, 830) being adapted to obtain an image of the object, wherein said image comprises pixels, and wherein each pixel of said obtained image has at least one of a color characteristic and a gray level characteristic depending on a local wavefront slope of a corresponding imaged region of said object; f. a processor connected to said imaging system and adapted to construct a map of the wavefront exiting said object by corresponding said at least one of a color characteristic and a gray level characteristic of said pixels to said wavefront slope, thereby said gradient inspection system being adapted to deterioring at least one of optical and geometrical properties of said object: wherein the gradient element is arranged in the optical system such that the gradient feature is in a linear spatial domain (f(x,y)) at planes (A1, A5) conjugate with said at least one aperture stop while said gradient feature is in an angular domain (f(α,β)) at planes (A2, A3, A4, A6) conjugate with said object. a. an illumination system (204, 404, 504, 615, 740) constructed and configured to illuminate said object such that each point of said object receives a similar angular distribution of light; b. an imaging system (212, 414, 542, 602, 702, 802) constructed and configured to image said object onto an image plane; c. at least one aperture stop (214, 420, 514, 604, 708, 804) of said imaging system; d. a gradient element (202, 402, 502, 606, 808, 1204, 1206, 1208) comprising at least two distinct areas, each area enabling a passage of light of at least one of a defined gradient feature being a measurable characteristics, therethrough, selected from spectrum and power, said gradient element being disposed in at least one of said at least one aperture stops of said imaging system; e. a sensor (216, 422, 546, 612, 706, 830) disposed in said image plane of said imaging system, said sensor being capable of differentiating between said at least two distinct areas of said gradient element (202, 402, 502, 606, 808); and said sensor (216,446, 546, 612, 620, 830) being adapted to obtain an image of the object, wherein said image comprises pixels, and wherein each pixel of said obtained image has at least one of a color characteristic and a gray level characteristic depending on a local wavefront slope of a corresponding imaged region of said object; f. a processor connected to said imaging system and adapted to construct a map of the wavefront exiting said object by corresponding said at least one of a color characteristic and a gray level characteristic of said pixels to said wavefront slope, thereby said gradient inspection system being adapted to deterioring at least one of optical and geometrical properties of said object: