In certain embodiments, a system for making an implant for an eye comprises a printer, a camera, and a computer. The printer prints material onto a target and has a printer head and printer controller. The printer head deposits the material onto the target, and the printer controller moves the printer head to deposit the material onto a specific location of the target. The camera generates an image to monitor the printing of the material. The computer stores a pattern for the implant, which is designed to provide refractive treatment for the eye； sends instructions to the printer controller to move the printer head to print the material onto the target according to the pattern； assesses the image from the camera according to the pattern； and adjusts the instructions in response to the image.
