Many friends who want to have myopia surgery may often hear a word in the process of learning about myopia surgery:Dark pupils
So, what is a dark pupil?
In the middle of the "black eyeball" of the eye, there is a small round hole, which is the path of light into the human eye, which is the pupil.
The "dark pupil" refers to the size of the pupil in a dark environment.
Everyone's pupil size is different, related to age, race, etc., and a person's pupil size is not static, it mainly changes adaptively with the brightness and darkness of light.
Before myopia surgery, a standardized and comprehensive preoperative examination should be done, one of which is to measure the dark pupil.
The size of the pupil affects the amount of light entering the eye, and when the pupil is large, the ocular aberration increases, which affects the imaging quality of the human eye.
Therefore, dark pupil measurement is an important examination item before myopia surgery. The larger the pupil, the more light enters the eye and the more severe the glare.
So, how big is a dark pupil considered normal?
Most adults have a dark pupil size of 6Within 5mm, there are also a small number of people with dark pupils greater than 65mm。
And as a person ages, the dark pupils may gradually decrease.
Whether it is laser surgery or ICL lens implantation surgery, there is a ** light zone.
Theoretically, the best visual effect is achieved when the light area of the surgery completely covers the maximum area of the dark pupil. If the size of the dark pupil exceeds the size of the optical area, there is a high probability of glare, halo, and poor night vision after surgery.
Glare refers to a visual phenomenon in the field of vision that causes visual discomfort and reduces the visibility of objects due to inappropriate brightness distribution or a relatively large brightness difference in space or time.
It can be understood in this way: due to the large difference in brightness and darkness in front of the eyes, the eyes are not comfortable to see, and the glare is generally more obvious at night.
But glare is a subjective concept, and there are differences in individual perceptions.
The dark pupils are large, and there may not be glare after surgery.
In practice, some myopic friends have dark pupils of more than 75mm, but there was no severe glare or other nighttime discomfort after surgery.
Because individuals have certain differences, each person reacts and adapts to glare differently. Some friends with large dark pupils will have glare before surgery even if they do not have myopia surgery, and some people will have glare even though they have small dark pupils.
In fact, the factors that cause glare are are very complex, and the dark pupil is only one of the factors, so there is no need to worry too much about the size of the dark pupil.
Many myopic friends find that the dark pupils are large during the preoperative examination, and they will worry about whether they can have laser surgery and whether there will be problems such as glare.
In this case, an experienced doctor will formulate a personalized surgical plan according to the degree of myopia, corneal thickness, dark pupil size, etc., so as to reduce the occurrence and degree of postoperative glare as much as possible. Flat-topped mountains are femtosecondDeclaration:
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