To identify associations between crystalline lens-related factors and central vault after Implantable Collamer Lens (ICL) (Staar Surgical, Monrovia, CA) implantation.This retrospective clinical study included 320 eyes from 186 patients who underwent ICL implantation surgery. At 1 year after surgery, the central vault was measured using anterior segment optical coherence tomography. Preoperative anterior chamber depth, lens thickness, lens position (lens position = anterior chamber depth + 1/2 lens thickness), and vault were analyzed to investigate the effects of lens-related factors on postoperative vault.The mean vault was 513 ± 215 µm at 1 year after surgery. Vault was positively correlated with preoperative anterior chamber depth (r = 0.495, P < .001) and lens position (r = 0.371, P < .001), but negatively correlated with lens thickness (r = -0.262, P < .001). Eyes with vaults of less than 250 µm had shallower anterior chambers, thicker lenses, and smaller lens position than eyes in the other two vault groups (which had vaults ≥ 250 µm) (P < .001). Eyes with both anterior chamber depth less than 3.1 mm and lens position less than 5.1 mm had greatly reduced vaults (P < .001).The crystalline lens could have an important influence on postoperative vault. Eyes with a shallower anterior chamber and a forward lens position will have lower vaults. [J Refract Surg. 2017;33(8):519-523.].