Astigmatism is a relatively common refractive abnormality, and patients with astigmatism also need to wear contact lenses. So, in the case of astigmatism, how to match contact lenses?
Astigmatism is mostly caused by congenital factors, and is often accompanied by myopia and hyperopia. Due to the irregular shape of the lens, the light entering the eye cannot be focused on the same point. Myopia and hyperopia are mainly due to the fact that light can only be focused in front or behind the retina under the action of refraction, so it is possible to see clearly even with squinting when the degree is low. However, astigmatism actually produces images that are not blurred but ghosted, so no matter how much you squint, you cannot see clearly.
The human eyeball may not be perfectly round all the time, so everyone will have some symptoms of astigmatism more or less. When the astigmatism is less than 75 degrees, it does not affect the vision very much under normal circumstances. If the need for correction is not large, ordinary contact lenses can meet the needs of daily life.
If the degree of astigmatism is high, it is necessary to conduct a glasses evaluation under the supervision of a doctor, and also need to determine the axial position and luminosity of astigmatism through optometry, and then customize astigmatic contact lenses. The degree between contact lenses and frame glasses needs to be converted, and the axis and degree of astigmatism cannot be simply added or subtracted. It is recommended that you try to customize astigmatic contact lenses in an eye hospital, and try them on under the guidance of a doctor.
In fact, astigmatism is difficult to avoid through prevention, and early detection and correction are required to avoid problems such as amblyopia and torticollis. If you suffer from astigmatism, in addition to reasonable correction, you should also develop good eye habits.