What is the cause of pupil dilation?

Many times some people's pupils are dilated without them knowing it. The most common and most common thing is that when we see something we like, our pupils will dilate unconsciously. This is understandable because after all, we see something we like. But there is a certain scientific basis for why our pupils dilate at normal times.

If you are a man, when you see the girl you like, your heartbeat will surely accelerate, and your pupils will definitely dilate. However, many times, the occurrence of some diseases is also accompanied by symptoms of pupil dilation. At this time, people should be vigilant.

Many times, some cranial and brain diseases can cause pupil dilation, disappearance of pupil light reflex, disappearance of corneal reflex, etc. However, when humans are excited by external stimuli, their pupils will dilate. In daily life, people are most exposed to the use of drugs such as atropine to dilate the pupil when testing vision, and in optometry, it is used to eliminate the influence of pupil reflex during the eye examination process.

In addition to the influence of pathological factors, pupil dilation is sometimes an instinctive protective reaction of the body. Sometimes, a person's psychological activities can be guessed through changes in the pupil. Under normal circumstances, the pupil is a contractible hole in the iris of the eye, and it is round whether it is expanded or shrunk.

The pupil not only responds to light and darkness and adjusts the light entering the eye, but also affects the depth of focus and spherical aberration of the eye's optical system. The range of pupil changes can be very large. When extremely contracted, the diameter of the human pupil can be less than 1mm, and when extremely dilated, it can be greater than 9mm. The iris sphincter can shrink to 87% of its length, which is almost impossible for other smooth muscles or striated muscles in the human body to achieve. The pupil will adjust its size according to the intensity of external light. When the light is strong, the pupil becomes smaller, and when the light is weak, the pupil becomes larger. This is a self-protection for the eyes.

Doctors also consider the pupil to be a sensitive indicator of vital functions. As we all know, the pupil will automatically shrink when the light is strong, and dilate when the light is dim - this is called the pupil's response to light. If the pupil's response to light becomes slow or absent, it means death is imminent. For comatose patients, their pupils will gradually dilate as their loss of consciousness worsens. Complete dilation is a sign of the end of life.

What’s even more interesting is that changes in pupil size reflect certain psychological activities. Whenever there is a strong interest or motivation, the pupil will expand rapidly. Ancient Persian jewelers charged prices for jewelry based on the size of the customer's pupils. If the sparkle of a diamond ring can make the buyer's pupils dilate, the dealer will charge a higher price.

Understanding what pupil dilation is can help us better help others and protect ourselves. When someone's life is threatened, the pupil dilates and the light reflex and corneal reflex disappear. At this time, we must provide timely rescue. When encountering factors such as strong light that affects the eyes, we can also protect ourselves by adjusting the size of the pupil.

To sum up, apart from the influence of disease, the dilation or contraction of pupils can reflect a person's psychological activities and thoughts. Through this article, we also have a deep understanding of what pupil dilation is all about. Therefore, in the future life, if we encounter the same situation, we can understand the mystery.