The contraindication for refractive error is that both eyes should not be more than 250 diopters, otherwise there will be difficulty in fusion due to the unequal size of the objects in both eyes. If the difference in refractive error is not large, it can be adequately corrected with frames, which can be worn frequently to maintain monovision in both eyes. If the refractive error is greater than 250 degrees, a trial of corneal contact lenses can be used to overcome the interference of different images, or excimer laser refractive corneal surgery can be performed. If the refractive error is aniridia, consider IOL implantation.