Objective To compare wavefront aberrations, pupil size, and accommodation of Chinese myopes and emmetropes during reading.
Methods  Fifty-eight adult subjects (17 emmetropes and 41 myopes) viewed RSVP text binocularly at 40, 33, and 25 cm viewing distances while accommodative responses and pupil diameters were measured with a Grand Seiko WV-500 autorefractor. Wavefront aberrations were measured during accommodation to the text using a WASCA wavefrontanalyzer.
Results Accommodative lag and pupil size were larger in the myopic group than in the emmetropic group (lag: 25 cm, P<0.05; pupil: 33 cm, P<0.05; 25 cm, P<0.01). With fixed pupil, wavefront aberrations did not differ with viewing distance, or between myopes and emmetropes. When analyzed with the natural pupil, total RMS (2^nd to 7^th order excluding defocus), higher order RMS (3 ^rd to 7^th order), astigmatism, Z7 coma, and Z6 and Z9 trefoil decreased significantly at nearer distances (p<0.01). When accommodative demand was 25 cm, myopes’ total RMS, higher order RMS, astigmatism, spherical aberration, and coma were higher than those of the emmetropes (p<0.01 in each case).
Conclusion Myopes had larger accommodative lags and pupils than emmetropes during high accommodative demand. Higher accommodative lags and higher aberration levels due to larger pupils can degrade myopes’ image quality during reading. If present in Chinese children, these effects might influence myopia onset and progression.