Abstract: A surgical cassette has rigid walls for collecting aspirated tissue and fluid and for operable communication with a fluid level detection system of a surgical console, in which the surgical cassette is placed. The surgical cassette has an interior volume, defined by the rigid walls, to hold the aspirated tissue and fluid. A plurality of prisms are formed on an interior of at least one rigid wall, at a location, such that the prisms are in operable communication with the fluid level detection system, when the surgical cassette is placed in the surgical console. An exterior of the rigid wall corresponding to the location of the plurality of prisms is coplanar with an exterior of the rigid wall not corresponding to the location of the plurality of prisms.