A comparison of visual symptoms after reading text from computer screen and hard copy.

Abstract

Purpose:

 The basic purpose of this study was to evaluate the association of asthenopic symptoms with prolonged computer use or sustained near work and its comparison with hardcopy (printed material) and to find out the change in accommodation and convergence due to its association with asthenopic symptoms.

METHOD:

A comparative cross sectional study was conducted in emetropes. This study consists of 30 young participants who performed test on computer screen and hard copy for consistent 40 minutes. And the working distance maintained was 30cm. After completion of test they were asked to fill self-designed proforma with question regarding their visual discomfort after performing test from computer screen and hard copy.
RESULTS:

Final results indicated that overall percentage of change in visual symptoms were greater in computer users than hard copy. 40% participants reported blurring of vision and headache from computer and 30% from hard copy. And 63.33% participants felt eyestrain and irritation in eyes from computer screen and 36.67% from hard copy.53.33% felt discomfort in eyes from computer screen and 40% from hard copy. Results obtained through paired sample t-test revealed that there was a significant change in p-values of NPC and NPA. P-value of NPC obtained after reading from soft copy was.001 and p-value of NPA was .003 while the p-value of NPC obtained after reading from hard copy was .002 and .040 p-value of NPA was observed.

CONCLUSION:

Results demonstrated that accommodation fatigue has a marked impact on visual discomfort while doing near work. But higher percentage of asthenopic symptoms was observed during computer screen. And it shows that even use of modern VDT or computer screen still causes visual discomfort as shown in results. So it is comparatively easy to read from hard copy than from computer screen.