The aim of this study was to investigate the clinical outcomes of conjunctiva-Müller muscle resection (CMMR) in patients with mild to moderate ptosis, the factors related to successful procedures, and the influence of CMMR on dry eye symptoms and signs. In a tertiary university hospital, the medical records of 30 patients who had CMMR were retrospectively reviewed, including the detailed preoperative and postoperative eyelid measurements, surgical outcomes, and dry eye evaluations. Inclusion criteria included older than 18 years, acquired ptosis, and no previous eyelid surgery or trauma. The surgery had a success rate of 86.7%. In the patients who responded to phenylephrine application with a marginal reflex distance 1 (MRD1) increase of more than 2 mm, the postoperative MRD1 correction was 2.41 ± 0.84 mm, whereas the postoperative MRD1 correction was 1.19 ± 0.78 mm in the group with responses of less than 2 mm. The postoperative MRD1 correction was 1.21 ± 0.80 mm in the group with a negative response. Seven patients complained of dry eye symptoms and showed a transiently significant aggravation in the Schirmer test and ocular surface disease index score after the procedure, which normalized within 2 months postoperatively. Responsiveness to phenylephrine is directly correlated with the postoperative results. Nevertheless, even in the patients with negative phenylephrine response, some degree of eyelid elevation can be expected. Damage to goblet cells after the procedure may result in defective tear production, leading to transient aggravation of dry eye symptoms.