A comparison of accommodation and ocular discomfort change according to display size of smart devices

BMC Ophthalmology

Table 3 Change of objective accommodative response before and after use of smart devices

	Pre	Post Smartphone	P value^a	Difference (Pre–Post)	P value^b
	Pre	Tablet	P value^a	Difference (Pre–Post)	P value^b
Refractive response (D)
At 1 m	-0.84 ± 0.40	-0.99 ± 0.68	0.103	0.15 ± 0.63	0.341
At 1 m	-0.84 ± 0.40	-0.95 ± 0.76	0.232	0.11 ± 0.64	0.341
At 67 cm	-1.64 ± 0.47	-1.72±-0.69	0.404	0.07 ± 0.58	0.002
At 67 cm	-1.64 ± 0.47	-1.58 ± 0.79	0.489	-0.06 ± 0.63	0.002
At 33 cm	-2.07 ± 0.80	-2.12 ± 0.85	0.577	0.06 ± 0.68	0.363
At 33 cm	-2.07 ± 0.80	-2.07 ± 0.94	0.944	0.01 ± 0.63	0.363
Accommodative facility (D)^c	1.23 ± 0.55	1.13 ± 0.50	0.241	0.10 ± 0.55	0.847
Accommodative facility (D)^c	1.23 ± 0.55	1.12 ± 0.57	0.199	0.11 ± 0.56	0.847

NPA Near point of accommodation, NPC Near point of convergence
^ap value by paired t-test of comparison between pre-and post-test using smart devices
^bp value by paired t-test of comparison between smart phone and tablet
^c Accommodative facility = difference between refractive responses at 1 m − 33 cm

ISSN: 1471-2415