In response to the special requirements of summer high school students’ examinations and military examinations, especially many parents and students are particularly concerned about femtosecond laser surgery, we have compiled the following common questions, which we hope will be helpful to you. Q: What is “femtosecond”? A: Femtosecond is a laser that operates in pulses of very short duration, one femtosecond is one trillionth of a second, which is the first characteristic of femtosecond laser. The second characteristic is a very high instantaneous power, can reach a million billion watts, than the world’s total power generation is more than a hundred times. The third feature is that it can focus to a region of space smaller than the diameter of a hair, making the electromagnetic field several times stronger than the force of an atomic nucleus on its surrounding electrons. In the medical field, femtosecond lasers can be used as ultra-precise surgical scalpels and have been successfully applied in the field of ophthalmology. Therefore, myopic laser surgery using “femtosecond” is more precise and safer. Wang Hui, Ophthalmologist, Chongqing Southwest Hospital Q: Is femtosecond laser surgery safe? A: Compared to previous surgical methods, the biggest advantage of femtosecond laser surgery is that it can create a very precise corneal flap, whose accuracy (average fluctuation: 10-15um) is three times higher than the accuracy of laminar knife (average fluctuation: 30-45um), and the actual probability of corneal flap complications is tens of thousands of times lower. In addition, the negative pressure of the suction ring used to create the corneal flap with the femtosecond laser (about 35 mmHg) is significantly lower than the negative pressure used to create the flap with the mechanical corneal laminotome (about 65 mmHg). Femtosecond laser surgery, therefore, can greatly improve the safety of quasi-surgery, especially for patients with thin corneas, large corneal curvature variation, and high myopia is a great boon. Q: What are the most serious complications that occur with femtosecond laser surgery? A: Femtosecond laser surgery, because it does not require a mechanical blade to make the corneal flap, can eliminate almost all serious complications caused by flap making. From the results of the nearly 300,000 femtosecond LASIK procedures that have been performed, no serious complications related to the procedure have been identified. Q: How long has femtosecond laser surgery been performed? A: The femtosecond laser has been FDA approved since 2002, and our center spent nearly $10 million to introduce femtosecond equipment in 2011. Since its establishment in 1997, the center has successfully performed more than 80,000 surgeries. Q: Is there any pain during the femtosecond laser surgery? A: Femtosecond laser surgery is different from conventional excimer laser surgery in that the flap is made differently and the laser cutting is the same after the flap is made. The surgery is performed under surface anesthesia, i.e., two drops of eye drops are all that is needed during the surgery. There is a transient black haze and a feeling of pressure and distension during the flap making process, and there is no significant pain.