In cataract surgery, patients may have eyes that dilate insufficiently. A typical cataract is roughly 1 cm in diameter, and the anterior capsulorrhexis may be around 5–7 mm, so a small pupillary opening makes the surgery significantly more difficult. Small pupils are a well-recognized risk factor in cataract surgery, increasing the risk of iris trauma, anterior capsular tear, posterior capsule rupture, vitreous prolapse, and retained lens material. Even when the iris does not appear to dilate poorly, it may have poor tone and be easily distorted by intraocular fluidics. The same fluid forces may stretch and drag iris through cataract wounds, leading to iris prolapse (Hausheer JR, ed. Basic techniques of ophthalmic surgery, 3rd ed. American Academy of Ophthalmology, 2019). Achieving adequate pupillary dilation is important to ensure seamless surgery, maximize patient safety, and reduce surgeon stress. Thankfully, numerous techniques have been developed to promote adequate pupillary dilation during cataract surgery. In this chapter, we review a systematic approach to manage the iris during surgery.