It is perfectly normal to have a refractive error of 75 degrees after dilating the pupils, and 50 degrees after reexamining the pupils. Refractive error is a common ophthalmologic condition that usually develops in childhood or adolescence and includes three different types of myopia, hyperopia, and astigmatism. In order to exclude the effect of ciliary muscle regulation within the eye, it is usually necessary to do a dilated pupil examination, that is, to paralyze the ciliary muscle with drugs such as cotrimoxazole, completely eliminating the regulation of the ciliary muscle, and only then can the optometry get the most accurate number of diopters. After the pupil returns to normal size, that is, after the effect of the drug completely disappeared and then carry out the optometry, the degree will have a certain degree of error with the real degree of error, so at present after the pupil dilation of the optometry has 75 degrees of refractive error, the pupil returns to normal size and then carry out the optometry has 50 degrees of refractive error belongs to a completely normal phenomenon. Does not affect the naked eye vision, you can first observe, if the naked eye vision can not meet the standard, it is recommended that under the guidance of the doctor for prescription correction to improve vision.