Mechanical tools are transparent in the sense that their input-output relations can be derived from their perceptible characteristics. Modern technology creates more and more tools that lack mechanical transparency, such as in the control of the position of a cursor by means of a computer mouse or some other input device. We inquired whether an enhancement of transparency by means of presenting the shaft of a virtual sliding lever, which governed the transformation of hand position into cursor position, supports performance of aimed cursor movement and the acquisition of an internal model of the transformation in both younger and older adults. Enhanced transparency resulted in an improvement of visual closed-loop control in terms of movement time and curvature of cursor paths. The movement-time improvement was more pronounced at older working age than at younger working age, so that the enhancement of transparency can serve as a means to mitigate age-related declines in performance. Benefits for the acquisition of an internal model of the transformation and of explicit knowledge were absent. Thus, open-loop control in this task did not profit from enhanced mechanical transparency. These findings strongly suggest that environmental support of transparency of the effects of input devices on controlled systems might be a powerful tool to support older users. Enhanced transparency may also improve simulator-based training by increasing motivation, even if training benefits do not transfer to situations without enhanced transparency. (Contains 3 tables and 6 figures.)