The black dot in the centre of your eye – this is your pupil. In reality, what this is, is a round opening in the iris that allows rays of light to enter the eye and it only appears to be black in colour.
Pupil – something not unlike the aperture on your camera
The size of the pupil normally changes throughout the day for various reasons. One of the most common causes is a reaction to light intensity. As a result of changes in light intensity we may notice its narrowing or expanding. This is how the pupil regulates the amount of light that penetrates the eye. It works identically to an automatic aperture on your camera. The pupil of the eye, just like the aperture of the camera, expands with insufficient light and retracts with intense light. These changes are a normal and natural reaction of the eye to its surroundings.
The pupil changes its size
The width of the pupil may also be affected by stressful situations, some diseases, medication, alcohol, or drugs. When the pupil dilates in reaction to narcotics it will retract of its own accord within a couple of hours as the effects wear off. A greater retraction of the pupil normally occurs in older people who often see worse at dusk as a result.
When to seek medical attention?
The pupil can reveal the fact that something is not right with our body. There are times when the changes in the size of the pupil indicate danger and we should take this sign as an indication to pay increased attention. One such instance is when poison is ingested. The pupils dilate for example with mushroom poisoning. In the most serious of cases these situations may be life-threatening and as such timely recognition of the problem may be a matter of life or death. Dilation of the pupil may also indicate a stroke, brain oedema, bleeding inside the skull or a brain tumour. It also often associated with injuries such a skull fracture or head trauma.
Many causes of the changes of the size of the pupil are normal, common, and harmless and as such there is no need to worry. In some cases, however, it is vital to seek out medical help especially when the dilated pupils are just one symptom accompanied by other complications. Have you noticed something like this o yourself or on someone in your vicinity? Then please do not hesitate to seek out an opinion of a specialist.