A: To save your time, you can prepare for each of the following before coming to the hospital: (1) Stop wearing contact lenses in advance (1 to 2 weeks for soft, 2 to 3 weeks for OK lenses and 3 to 6 months for OK lenses). (2) For female patients, please avoid periods of menstruation, pregnancy and breastfeeding. (3) Please make good arrangements for work and life. If possible, you can call ahead for consultation and we will give you detailed instructions. Xin Yijing, Ophthalmology, The First Hospital of Xiamen University