Effects Of Different Word Size, Spacing And Paper Color On Ocular Accommodation

Objective: To study the effect of the word size, word spacing, line spacing and paper color on ocular accommodation.Methods:1. Eighty participants were classified into three groups:emmetropes (n=16), low myopes (n=44), moderate myopes (n=20).2. Eighty participants underwent five kinds of reading materials:the first reading material (control group, word size:9.Opt, word spacing:0.0pt, line spacing:1.0times, paper color:white), the second (increase word spacing:1.0pt), the third (increase line spacing:1.5times), fourth (increase word size:12.0pt), fifth (change paper color:green). Daily continue reading time for40min, total five day.3. Before and after reading, the following parameters were measured:Accommodative response, Negative relative accommodation, Positive relative accommodation, Amplitude of Accommodation, Accommodative facility.4. Statistics processing:the same reading material in different refractive group, comparison of accommodative parameters before and after reading adopt independent sample t test; different reading material in the same refractive group, comparison of accommodative parameters after reading adopt paired t test. p<0.05mean differences with statistical significance.Results:1. Reading induce that accommodative lag add and amplitude of accommodation reduce;2. The same reading material in different refractive group, comparison of accommodative parameters, differences with not statistical significance.3. Different reading material in the same refractive group, comparison of accommodative parameters, there was a significant effect of word size (p<0.05) and word spacing (p<0.05) but not line spacing (p>0.05) and paper color (p>0.05) on accommodation.Conclusion:1. Reading induce accommodative lag add and amplitude of accommodation reduce;2. Increase word size or spacing would induce useful effect on accommodation.