{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T08:17:26Z","timestamp":1770884246497,"version":"3.50.1"},"reference-count":0,"publisher":"Press of International Journal of Ophthalmology (IJO Press)","issue":"3","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int J Ophthalmol"],"published-print":{"date-parts":[[2026,3,18]]},"abstract":"<jats:p>AIM: To investigate the effects of binocular fusional C-optotypes (positive\/negative) and 2D planar C-optotypes on the amplitude and stability of transient accommodation (TAC) in adults, and to provide a basis for non-contact myopia intervention.\nMETHODS: This was a self-controlled study. Using red-blue 3D technology, four experimental stages were set up: Test A [fixating on the 1 m negative fusional C-optotypes, 8\u25b3 base-in (BI)], Test B (fixating on the 5 m planar C-optotypes), Test C (fixating on the 1 m planar C-optotypes), and Test D [fixating on the 1 m positive fusional C-optotypes, 20\u25b3 base-out (BO)]. A WAM-5500 open-field autorefractor was used to measure TAC and accommodative microfluctuations [evaluated via interquartile range (IQR) and median-based coefficient of variation (CVmed)]. Additionally, the convergence accommodation to convergence (CA\/C) ratio was calculated, and a visual fatigue questionnaire was administered to assess participants' subjective visual comfort.\nRESULTS: A total of 21 subjects (7 males, 14 females; aged 23-41y) with normal binocular visual function were enrolled. The results showed that the TAC increased gradually across the four stages, and these values were Test A (-0.35\u00b10.26 D)&amp;#x003C;Test B (-0.46\u00b10.24 D)&amp;#x003C;Test C (-0.77\u00b10.32 D) &amp;#x003C;Test D (-1.38\u00b10.31 D). There were significant overall differences (F=56.136, P&amp;#x003C;0.001). Compared with Test C, Test A reduced TAC by 0.42 D (P&amp;#x003C;0.05), while Test D increased it by 0.61 D (P&amp;#x003C;0.001). There was no significant intergroup difference in accommodative fluctuation amplitude (all P&amp;#x003E;0.05), but the fluctuation stability of Test D showed a significant difference between the first 20s and the second 20s (P=0.017). The CA\/C ratio was significantly higher in Test D (0.05\u00b10.02 D\/\u25b3) than in Test A (0.03\u00b10.02 D\/\u25b3, P=0.007), indicating stronger accommodation-convergence linkage during positive fusional fixation. The visual fatigue scores of all stages were low (median 0-1), with Test D slightly higher than Test B and Test C (P&amp;#x003C;0.05). No linear correlation was found between TAC and age (all r&amp;#x003C;0.1, P&amp;#x003E;0.05).\nCONCLUSION: Negative fusional C-optotypes induce ciliary muscle relaxation to reduce TAC, while positive fusional C-optotypes enhance accommodation-convergence coordination to increase TAC. The red-blue 3D-based non-contact training mode exhibits good safety (median visual fatigue scores: 0-1 across all tests) and provides a novel dual-directional (relaxation-activation) strategy for myopia prevention and control.<\/jats:p>","DOI":"10.18240\/ijo.2026.03.15","type":"journal-article","created":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T07:23:54Z","timestamp":1770881034000},"page":"539-548","source":"Crossref","is-referenced-by-count":0,"title":["Positive\/negative binocular fusional C-optotypes and 2D planar C-optotypes on transient accommodation and stability in adult eyes: implications for myopia prevention and control"],"prefix":"10.18240","volume":"19","author":[{"name":"Eye Research Department, Dalian Medical University, Dalian 116044, Liaoning Province, China; Clinical Research Center, He Eye Specialist Hospital, Shenyang 110000, Liaoning Province, China","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qing-Xia","family":"Fan","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ling","family":"Xu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"name":"Clinical Research Center, He Eye Specialist Hospital, Shenyang 110000, Liaoning Province, China","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"He","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"name":"Eye Research Department, Dalian Medical University, Dalian 116044, Liaoning Province, China; Clinical Research Center, He Eye Specialist Hospital, Shenyang 110000, Liaoning Province, China","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"7543","container-title":["International Journal of Ophthalmology"],"original-title":[],"link":[{"URL":"https:\/\/www.ijo.cn\/gjyken\/article\/pdf\/20260315.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,12]],"date-time":"2026-02-12T07:55:14Z","timestamp":1770882914000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ijo.cn\/gjyken\/article\/abstract\/20260315"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,18]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2026,3,18]]}},"URL":"https:\/\/doi.org\/10.18240\/ijo.2026.03.15","relation":{},"ISSN":["2222-3959","2227-4898"],"issn-type":[{"value":"2222-3959","type":"print"},{"value":"2227-4898","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,18]]}}}