Data is received characterizing a result of a first visual sensitivity test assessing capacity to detect spatial form across one or more different target sizes, and different contrasts. Using the received data, one or more first parameters defining a first estimated visual sensitivity for a first range of contrasts and a second range of spatial frequencies is determined. One or more second parameters defining a second estimated visual sensitivity for a third range of contrasts and a fourth range of spatial frequencies is determined using the one or more first parameters and a statistical inference by at least presenting a first visual stimulus, receiving a response, and determining a second visual stimulus based at least on the response and at least a rule. The one or more second parameters is provided. Related apparatus, systems, techniques and articles are also described.