Device for improving quantification of reading acuity and reading speed

Purpose: To present a new device, the Salzburg Reading Desk (SRD), for the standardized testing of reading acuity and reading speed at a subjectively convenient reading distance (best distance).

Methods: First, in a systematic experimental setup, testing for validity and reliability was performed at 450 simulated reading distances (90 different test situations, each repeated 5 times) between 16 and 70 cm. The distance read-outs by the SRD software were correlated to the distances measured with a meter ruler. Second, reading distance and reading speed of 27 naturally emmetropic and presbyopic patients were evaluated using the log-scaled Radner Reading Charts implemented in the SRD.

Results: In the experimental setup, an overall mean difference of the SRD distance read-out-compared to a standard distance measurement with a meter ruler-of 0.08±0.13 cm was observed. In the presbyopic patients, overall mean reading distance was 49.74±4.43 cm. Patients were able to read with their own subjectively convenient reading distance. A constant mean reading speed of sentences with bigger typeface (between 152.4±22.6 words/minute [wpm] and 157.3±15.8 wpm) was found, but reading speed gradually diminished over time when reading sentences with smaller typeface.

Conclusions: The SRD seems to be a valid and reliable device for testing reading acuity at the best reading distance in an experimental setup as well as in clinical use in presbyopic patients. The SRD may be used whenever a detailed comparison of different methods for correcting presbyopia is required.