A light scattering sensor is provided with a cylindrical lens focusing received light along substantially parallel lines, or bands, that correspond to a range of scattering angles and a linear detector that detects the light intensity along the substantially parallel lines. By using a cylindrical lens, the lens serves as an auto-collimator, whereby light scattered at a specific angle from the collimated light beam strikes the linear detector at a corresponding specific location regardless of the location from where the light was scattered. Embodiments of the cylindrical lens-based light sensor can be applied to a number of different applications and industries that analyze light scattering intensity as a function of scattering angle. For example, embodiments of the cylindrical lens-based light scattering sensor can be used for monitoring a target fluid for contaminants.