Can orthokeratology prevent myopia?
It is said that when you sleep with such lenses, your myopia will disappear when you wake up in the morning. Do you know what the price is for such a magical effect? China's myopia degree is already 3: 00, 800 to 900 degrees. The doctor said that the number of people wearing glasses could be reduced. Eyes are not too tired, it is recommended to wear orthokeratology glasses. Xiao Zhi, a senior, said with a smile, I was prettier then. I think wearing glasses is ugly and I can't get a boyfriend. Seeing that many students around me are wearing orthokeratology lenses, I am envious and want to give it a try.
However, due to the depth of myopia, it is impossible to completely suppress the degree at first. After I put it on, I went back to the hospital for examination. One eye is still 200 to 300 degrees, and the other eye is still 100 degrees. You still have to wear ordinary glasses to see clearly during the day. In high school, the pressure of homework increases, and it is inevitable that you will not get enough sleep, so that you often don't wear enough clothes. You can't throw away your glasses completely until a year or two later.
Ortho-K mainly wears specially designed ultra-high oxygen permeable hard contact lenses when sleeping at night. It uses the plasticity of corneal epithelium to press the cornea to center it (our black eyeball). The curvature of this area is flattened, and the imaging focus is adjusted to fall on the retina instead of in front of it due to the elongation of the eye axis. It is a non-invasive vision correction method, which does not require surgery and is relatively safe. Coupled with the slow rebound time of the cornea, once the curvature is stabilized, you can still have clear vision even if you don't wear any lenses during the day.
It may look perfect, but orthokeratology still has its limitations. Zheng Huichuan, director of ophthalmology department of Maikai Hospital, said that different brands have different restrictions. Generally speaking, the degree of myopia is between 400 and 600 degrees, and when the astigmatism is less than 200 degrees, the corneal shaping effect is better; Therefore, patients with high myopia like Xiao Zhi will still have residual degrees.
And he repeatedly stressed that this can only temporarily adjust the corneal curvature. If you want to have a clear vision, you must wear it continuously; And everyone's corneal softness is different. Some people wear it for 3 or 5 days, and the corneal curvature can be stabilized. ? After wearing it for 6-8 hours according to the instructions, it can keep clear to the naked eye 12- 14 hours; However, he has also met several patients, and it takes 1 to 2 weeks to gradually stabilize.
Can orthokeratology correct myopia?
Orthokeratology is a kind of hard contact lens, which is usually worn at night and taken off the next morning. Using the physical shaping effect of lens surface to reduce myopia and obtain good vision. However, the corrective effect of this myopia is temporary. If you want to keep good eyesight, you must insist on wearing it.
The central part of the orthokeratology mirror is designed to be slightly flatter than the central part of the cornea, but slightly steeper around the middle part. In this way, the lens will "flatten" and reshape the center of the cornea and "protrude" the center of the cornea. So as to form a micro concave lens effect, so that after the image of the external scene enters the eyes, the focus moves back to the retina, and the nearsighted can obtain clear and bright vision.
Possible risks of orthokeratology
Due to environmental and individual differences and other factors, even if orthokeratology lens is used correctly, there is still the risk of eye diseases such as corneal endothelial cell reduction and conjunctivitis. If you don't wear it as required, it will easily lead to the increase of eye secretions, eye congestion, vision changes, foreign body sensation and other phenomena, and increase the risk of eye diseases such as corneal ulcer, keratitis and corneal erosion. Delayed treatment may also lead to permanent vision damage.