Hyperopia and myopia form an enlarged blurred spot on the retina, so the vision is unclear, while astigmatism forms a diffuse halo on the retina. Myopia, hyperopia and astigmatism are collectively called ametropia.
Myopia and hyperopia are mainly due to the curvature of cornea and lens surface is too large (myopia) or too small (hyperopia), and the axial length is too long (myopia) or too short (hyperopia). Astigmatism is mainly caused by the curvature inconsistency of each meridian on the surface of cornea and lens. Hyperopia is mainly influenced by genes or heredity, while myopia is influenced by many factors, but environmental factors play a major role. Generally, corneal curvature, posterior surface curvature of lens and axial length are greatly influenced by heredity.
Of course, ametropia is also caused by the uncoordinated components of the refractive system. Some eye axes are not very long, but because the radius of curvature of cornea is too large, it also causes myopia. Some axial growth, but insufficient compensation for corneal development, also causes myopia.
Therefore, generally speaking, when there is exophthalmos, it is generally moderate to high myopia, accompanied by the phenomenon of long eye axis. Therefore, eyeball deformation has nothing to do with glasses, but is closely related to its own refractive state.
Contact lenses make up for the poor refractive system of eyes through the interaction between contact lenses and tears, thus correcting vision.
Theoretically, when glasses are worn in front of 15.07mm cornea, vision is real. However, due to the facial features of China people, most people wear glasses about 12mm in front of the cornea. Therefore, due to the unique optical characteristics of optical lenses, nearsighted lenses (concave lenses) have the characteristics of decreasing vision and becoming farther away, while hyperopic lenses (convex lenses) have the characteristics of seeing. After all, contact lenses are in direct contact with the cornea, so vision is more real and natural than frame glasses. However, contact lenses (contact lenses) are in direct contact with the cornea, so it will inevitably cause some damage to the cornea, especially for people who wear them for a long time. Therefore, it is generally recommended to wear contact lenses after adulthood, and wear them for no more than 10 hour every day. It is suggested to stop using contact lenses for a day or two to cultivate cornea and wear glasses instead.
Surgical treatment is a very popular method to treat myopia in recent years. Its principle is to cut a layer on the cornea to change its curvature and make it smaller, thus correcting myopia. But the cornea is only 0 after all. Five to zero. 7mm, and surgical treatment will also cause irreparable damage to the cornea, so its therapeutic effect often takes 10 to 20 years to see whether there are sequelae. The developed countries started the operation earlier than China, so many problems appeared earlier than China. Therefore, the second operation is controversial in developed countries abroad, and even some developed countries have legislated to ban it.
If you feel tired wearing frame glasses, it should be an optometry or assembly problem. It is recommended to go to a hospital or an optical shop with strong technical strength for optometry, instead of going to a small shop for fitting.
I hope I can help you. Please call me if you have any questions.