9/21/2023 0 Comments Normal pupil size child![]() ![]() If only one pupil changes size, there is usually a problem with the brain, or with the optic nerve (the nerve that runs from the brain to the eye). If both pupils change size at the same time, but the change happens slowly, the pupils are called "sluggish." This can be a sign of illegal drug use, hypoxia (not getting enough oxygen to the brain), or injury. This is called being "light-reactive" (the pupils are reacting to changes in light). When the light is taken away, both pupils should get bigger at the same time. When a light is shined in one pupil, both pupils should get smaller at the same time. ![]() When one pupil is a different shape, usually the person has had an injury to the eye. Usually, there is only a small difference in size. In these people, this is normal and does not signal a problem. However, up to 20% of healthy people have pupils that are different sizes. For example, their brain may be injured, or they may have had a stroke. Pupils that are "unequal" (one is bigger than the other) are usually a sign that something is wrong with the brain. In most healthy people, the pupils should be the same size ("equal"). They are hypoxic (their brain is not getting enough oxygen)Ī person's pupils may also be dilated if they are in a dark place, or if they have used some kinds of eyedrops.Pupils that are both "dilated" (larger than usual, up to 8mm across) are a sign that a person may have one of these problems: They are bleeding in a part of their brainstem called the pons (this is very rare)Ī person's pupils may also be smaller than usual if they are in very bright light.They have been poisoned with a type of chemical called an organophosphate, which includes things like some pesticides as well as nerve gases like sarin.Pupils that are both "pinpoint" (the size of the point of the end of a pin - about 1mm across) are a sign that a person may have one of these problems: In humans, the pupil is round, but in some other animals, like cats, it is shaped like a slit. The reason why it has no colour is because the light that travels through the pupil is absorbed by tissues at the inside of the eye. The main reason why we have a pupil is to regulate the light which travels to the retina. The pupil is normally black in most animals, but in some reptiles, it can be a different colour. When it is bright, the pupil will constrict (get smaller) to restrict the amount of light there is getting into the eye so we can see. When it is darker, the pupils will dilate (get bigger) because they need to allow more light into the eye to see. The light makes the pupil change its size. The focus point is where the eye is focusing on. The lens changes its shape depending on how far away the eye focuses. It is surrounded by the iris which is the coloured part of the eye. The pupil can be compared with the shutter of a camera. In brighter light, the pupil is made smaller. When more light is needed, the pupil is made larger. There is a circular group, which squeezes the iris smaller, and another group which pulls the iris wider. ![]() The size of the pupil is controlled by muscles. Light enters through the pupil and goes through the lens, which focuses the image on the retina. The pupil is the opening in the centre of the eye. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |