Purpose To investigate the dynamic pupil and vault changes in eyes with implantable phakic contact lens (IPCL) under photopic and scotopic settings, as well as during accommodation using the anterior segment optical coherence tomography (AS-OCT). Methods A prospective observational study included consecutive 36 eyes of myopic patients who underwent IPCL V2.0 implantation. Under photopic and scotopic light settings, as well as during accommodation, all patients were scanned using CASIA OCT (CASIA2; TOMEY, Nagoya, Japan). The pupil size, the vault (distance between the back surface of the IPCL and the anterior lens capsule), ACD-lens (distance between the posterior corneal surface and the anterior lens surface), IPCL-lens (distance between the posterior corneal surface and the anterior IPCL surface), and lens thickness (LT) were the study parameters. Results The vault was significantly lower under photopic conditions ( p -value<0.001). The pupil size was significantly smaller in photopic conditions ( p -value<0.001). LT ( p -value=0.975) and ACD-lens ( p -value=0.917) were not significantly different between scotopic and photopic conditions, while the ACD-IPCL was significantly larger during photopic conditions ( p -value=0.013). There were significant changes in all parameters between accommodative and non-accommodative conditions. Conclusion The IPCL vault decreased significantly under photopic light conditions and accommodation.