Dilation, or widening, of the pupils of the eyes is normal in conditions of low light in order to allow more light to reach the retina. Medically, dilation of the pupils is known as mydriasis. Specific medications known as mydriatics are administered to dilate the pupils for ophthalmologic examination. If the pupils are dilated due to an abnormal response, they may remain dilated even in the presence of sunlight or strong light. Injury to the brain and taking certain drugs are common causes of abnormally dilated pupils. Both medications and drugs of abuse can result in dilated pupils. Dilation of the pupil on one side only is also abnormal and may signal a brain injury or other condition that raises the pressure within the cranial cavity (increased intracranial pressure).
Other causes of dilated pupils (mydriasis)
- Cerebral Edema
- Drug Overdoses
- Elevated Intracranial Pressure
- Elevated Intraocular Pressure
- Intracranial Hemorrhage
- Low Ambient Light
- Medications
- Poisonings
- Sexual Arousal
- Skull Fracture
- Trauma
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Causes of Dilated Pupils (Mydriasis)
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Drug Abuse and Addiction
Drug abuse and addiction is a chronic disease that causes drug-seeking behavior and drug use despite negative consequences to the user and those around him. Though the initial decision to use drugs is voluntary, changes in the brain caused by repeated drug abuse can affect a person's self-control and ability to make the right decisions and increase the urge to take drugs. Drug abuse and addiction are preventable.
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Head Injury (Brain Injury)
In the United States, head injuries are one of the most common causes of death and disability. Head injuries due to bleeding are generally classified by the location of the blood within the skull, these include epidural hematoma, subdural hematoma, subarachnoid bleed, intracranial bleed, sheer injury, edema, and skull fracture. Some common symptoms of a head injury include vomiting, bleeding from the ear, speech difficulties, paralysis, difficulty swallowing, and body numbness. Treatment of a head injury depends on the type and severity of the injury.
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Teen Drug Abuse
Drugs commonly abused by teens include tobacco products, marijuana, cold medications, inhalants, depressants, stimulants, narcotics, hallucinogens, PCP, ketamine, Ecstasy, and anabolic steroids. Some of the symptoms and warning signs of teen drug abuse include reddened whites of eyes, paranoia, sleepiness, excessive happiness, seizures, memory loss, increased appetite, discolored fingertips, lips or teeth, and irritability. Treatment of drug addiction may involve a combination of medication, individual, and familial interventions.
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