Digital cataract photography.

This study compares the cost effectiveness of two methods of grading cataract changes in the Australian population. The conventional film-based method has comparatively low set-up costs, but is more subjective in its assessment and more reliant on manpower, while the digital method has high set-up costs, but the results are more objective and available more quickly using fewer people. By a careful assessment of all the costs involved it is possible to estimate how many participants need to be recruited to a study in order to make the digital method cost effective.