to compare the amplitude of accommodation measured by printed vs digital charts

In this study, a total of 63 subjects (15-35 years of age) participated from Farhanghian clinic in Shiraz, Iran. The amplitudes of accommodation were measured by push-up technique. The lighthouse near number chart was used for printed format and an equivalent digital format was made on i-phone 7 plus. Five line with optotypes from 20/20 to 20/50 were used to measure the amplitude of accommodation.

The measured amplitude of accommodation for the pair of target sizes (print/ digital) from 20/20, 20/20/25, 20/30, 20/40, and 20/50 were: 9.23 ±1.72/ 9.67±1.68, 9.66±1.73/ 10.20±1.67, 10.27±1.73/10.83±1.65, 10.94±1.76/11.56±1.64, 11.52±1.79/12.16±1.59 respectively. Paired sample t-test analysis showed that the difference between two groups were statistically significant.

the values of the amplitude of accommodation measured by digital charts are more than the printed chart, showing that the perception of blur happens closer with digital targets. In clinics, when measuring the amplitude of accommodation with digital charts and trying to compare these results with printed charts norms this difference should be considered.