The dilation of pupils occurs sometimes naturally, as a defense mechanism of the body or sometimes under the influence of certain kinds of drugs and medication. It is therefore essential to find out the underlying cause for dilation of pupils as the treatment varies depending on what is causing the condition. Excessive pupil dilation is also termed as mydriasis and the condition is a response to illness, the use of certain types of drugs and trauma. The pupil dilates normally depending upon the amount of light present in the environment. In the daytime therefore, in the presence of a lot of sunlight, pupils generally constrict to protect the sensitive eyes from direct sunlight. In a dark room, or at night, the pupil dilates to allow for more light to enable better vision. Pupils are also believed to dilate as a response to immense sensual pleasure. Damage or trauma to the brain may cause pupils to dilate. Damage or trauma to the eyes may also cause pupils to dilate. If dilated pupils are symptoms that occur alongside certain others, it is an indication of an underlying medical condition. For instance, if the pupil of only one eye is dilated while the other does not respond to light or if dilated pupils occur alongside a feeling of weakness, changing speech patterns and an altered mental state, then this may be a sign of brain damage.
Always check the labels of medications and eye products like eye drops to ensure that pupil dilation is not a side effect. You can take recourse to changing your medication to help prevent pupil dilation caused by medication. Several over the counter drugs are also known to cause pupil dilation. Medications for an upset stomach or even motion sickness sometimes cause pupils to dilate. Avoid taking drugs like marijuana and cocaine – they are proven to cause pupils to dilate as a response of the central nervous system to the drug. Pupil dilation may also occur as a response to the poisonous secretions of certain plants. The bark of the black locust tree and other toxic chemicals present in the environment like jet fuel and chloroform may lead to pupil dilation. The cornea and conjunctiva are the protective coverings of the eye. Any foreign body or pollutant may irritate this protective covering and cause pupil dilation. Make sure you wash your eyes frequently and apply cleansing eye drops to get rid of any foreign particles.