A solution for optically evaluating a wheel along at least one circumference of the wheel is provided. Image data is obtained while the wheel moves along a path having a length of at least one circumference of the wheel. The path and/or wheel can be illuminated to enhance the resulting image data. One or more attributes of the wheel are measured based on the image data. The attributes can then be used to detect one or more defects in the wheel. In one embodiment, the wheel is a rail wheel, and a rail segment is illuminated. The rail can be specially configured to enhance a contrast between the rail and the rail wheel and/or to provide a consistent path for the rail wheel to travel.