Corneal shaping lenses have recently become very popular, not only because they are the most effective way to control the growth of myopia in teenagers, but also because they are the only “magic bullet” for non-surgical rapid vision improvement for college entrance exams, military recruitment, and civil service medical exams. Therefore, recently many people are inquiring, how much is your own optometry, can you wear keratoconus? It is difficult for me to answer such a question. Keratomileusis is a more complex technology in the field of optometry, in the national optometrist occupational standards belong to the highest occupational level of senior optometric technician requirements. Corneal shaping has certain restrictions on the conditions of the fitter, not everyone is suitable for corneal shaping. It is the doctor’s important duty to strictly screen the corneal shaping candidates, and it is the first step to a successful fitting. The examiner should always keep in mind that those who do not meet the requirements will not be forced to wear keratoplasty lenses. The main fitting population (screening guidelines) for keratoplasty are: Ocular: no eye disease, such as acute keratitis, glaucoma, corneal trauma, etc. No previous keratoconus surgery, etc. Intraocular pressure: IOP within normal value, 10-21 mmhg. Pupil size is normal, and pupil should not be too large (no more than 6mm) in dark light environment, otherwise it will easily cause glare at night. Systemic: No immunocompromising diseases Individual conditions: Good hygiene, good hygienic habits, compliance with doctor’s instructions, and ability to take care of oneself. Refractive conditions:myopia reduction within 600 degrees, cis-gauge astigmatism less than 175 degrees, retrogauge astigmatism less than 75 degrees, ratio of myopia to astigmatism greater than 2, corneal flat K value less than 46D, difference between corneal flat K value and desired myopia reduction greater than 36D, and central corneal E value greater than 0.3. Although we do a lot of tests during the initial examination such as questioning and general examination, optometry, etc., to There are some factors that cannot be confirmed during the eye examination and must be confirmed by trial fitting. The most common ones are: firstly, the upper eyelid is too tight, causing the lens to deviate upward and not be centered; secondly, the corneal surface is irregular, the tension is not uniform, and the lens is always to the left or to the right and not centered, even though the tightness is good. For these two types of patients, even if the initial examination shows that they are suitable for wearing keratoconus lenses, they still have to give up the fitting. As you can see, trial fitting is a very important part of the fitting process. Some fitters customize lenses based on only a few parameters or corneal topography parameters, not taking all factors into account. When such lenses are fitted to patients, a certain percentage of the population will have lenses that do not fit perfectly, resulting in safety problems. In contrast, a trial fitting procedure that identifies lenses that prove to be a good fit when actually worn can greatly increase the success rate of the first fitting. It’s like customizing clothes, you have to try them on after measuring them to make the best fit. In conclusion: Therefore, it takes a process to determine whether a person is suitable for keratoplasty, not just a simple consultation and examination. It takes more of a fitting process to determine, and sometimes this process takes 2 or 3 days. Of course, although the process is complicated: consultation, examination, optometry, fitting …… But through such a strict screening, once the fit is judged, then the fitting will be very good, with almost no complications and a very high success rate.