PURPOSE: To evaluate the efficacy of 3 cycloplegic regimens in adults with myopia. METHODS: Refraction, accommodation amplitude, residual accommodation and biometric findings were assessed before and after instillation of regimen I (tropicamide 0.5% and phenylephrine 0.5%), regimen II (cyclopentolate 1.0%), and regimen III (combination of regimen I and II). RESULTS: In myopic adults aged 22 to 26 years, cycloplegic refraction revealed less myopia than manifested refraction. Although there was no difference in residual accommodation among the 3 regimens, regimen II and III were more effective in reducing myopia, accommodation, and axial length. The difference in cycloplegic refraction between regimen I and II was more prominent in patients who had larger amplitude of accommodation and residual accommodation with regimen I. CONCLUSIONS: Cycloplegic refraction should be used even in adult myopes. For patients with stronger accommodation and larger residual accommodation with tropicamide, cycloplegic refraction with cyclopentolate may be used to ensure relaxation