Trial fitting is a very important step in the fitting process of keratoconus lenses. So, why do you need to try on keratoconus lenses? Here’s what ophthalmologists have to say. There are two main purposes of trying on keratoplasty lenses, one is to determine whether myopic patients are suitable for wearing keratoplasty lenses, and the other is to find out the most suitable lens brand, parameters and design for patients to wear. When we shop for clothes, we try on a group of finished clothes differentiated by size. Different sizes represent different combinations of parameters, such as collar size, waist size, chest size, cuff size, etc. Some of the garments are not suitable for the wearer, while most people can pick the finished garment that suits them. The keratomileusis standard lens set, on the other hand, is a set of finished lenses designed for different ophthalmic combinations, in which most people can pick the right lenses and a small percentage of people need to make adjustments. In addition, a lens designed based on only a few parameters or corneal topography does not take all factors into account. In the trial wearing process, we simulate the influence of the following factors on the lens fit during sleep, such as eyelid force, corneal diameter, corneal asymmetry, tear quality, corneal plasticity, fitting time, etc. We choose the matching lens parameters and design according to the trial wearing results to improve patient satisfaction and fitting success rate and ensure safety and effectiveness!