Astigmatism is a very common refractive error that, like nearsightedness and farsightedness, can bring many changes to everyday life. Astigmatism itself may develop into myopia, and the combined astigmatism in myopia may also promote the development of myopia and cause amblyopia, so astigmatism cannot be ignored. So, how to convert the degree of astigmatism when preparing contact lenses?
The formulation of astigmatism contact lenses is the same as that of ordinary contact lenses, but there are some differences. The degree of myopia is just a numerical value, so just follow the formula conversion or query the table to get the degree of contact lenses when you are wearing glasses. However, the preparation of astigmatic contact lenses requires two parameters, the degree and the axial position. In order to obtain a good fit, it is necessary for patients with astigmatism to perform basic examinations and optometry before glasses.
When fitting glasses, for the sake of convenience, some optical shops choose to add half of the astigmatism power to the converted contact lens power to prepare contact lenses, but this method is not conducive to vision correction, and long-term wearing of such contact lenses may cause greater discomfort.
In theory, contact lenses do correct mild astigmatism. If the degree of astigmatism is less than 75 degrees, it usually does not affect daily life, so there is no need to consider the degree of astigmatism, and ordinary contact lenses can be selected directly according to the degree of myopia. Otherwise, we still recommend that you go to a professional eye hospital with a pair of astigmatism contact lenses to avoid problems such as dizziness, headache, and increased degree due to the inappropriate degree.
Whether you wear ordinary contact lenses or astigmatism contact lenses, you must pay attention to eye hygiene. Daily use of mobile phones, computers and other electronic products should be minimized, and outdoor activities should be carried out more often, and the wearing time should be strictly controlled.