The Use of Task-Specific Lenses by Presbyopic Air Traffic Controllers at the En Route Radar Console.

The configuration of the radar console to control aircraft traffic has similar features to a visual display terminal (VDT) work station. Task-specific lenses have been found in clinical studies to reduce visual symptoms while working at the VDT. The American Optical Corporation TruVision Technica(TM), a task-specific lens design, was evaluated to see if visual benefits from such a lens could be transferred from the VDT environment to the radar console work environment. Presbyopic air traffic control specialists (ATCSs) were fitted with two prescription spectacles, using their current and Technica lens designs, in similar ophthalmic frames. Each ATCS used both lens designs at the radar console and provided subjective evaluations of their appropriateness in that environment. Thirteen subjects (36-55 years old) completed the study. Subjects who used larger near viewing area (single vision and executive) lens designs generally preferred their current lens design. The Technica was preferred by mature presbyopes (add power of equal to or greater than 1.25 diopters) and those using smaller near viewing area (FT-25, FT-28 and general progressive addition) lens designs. The primary complaints reported by ATCSs with the Technica were peripheral distortion and limited field of view. Task-specific lens designs are an alternative for presbyopic ATCS who work at a radar console. However, distortion and limited field of view from the lens may require prolonged adaptation times before such designs are acceptable to ATCS on the job, especially for those accustomed to lens designs with larger viewing areas.