The pupil is the large black circle that is in the center of each eye. It widens and narrows naturally in response to changes in the light. Pupils become larger in dim light to let in more of the image and smaller in bright light to limit the...
During an eye examination, the doctor looks through the pupils to physically inspect the anterior chamber of the eyes. By use of dilating drops, he can temporarily paralyze the muscles that control the iris, roughly doubling the size of the...
The pupil is the round black center of the eye. It is the opening that lets light into the eyeball. The colored iris surrounds the pupil. According to Ted M. Montgomery, O.D., the eye's pupil widens when the dilator muscles of the iris...
The pupil, the black spot in the center of the eye, is essentially a hole that allows light into the eye. The pupil enlarges and constricts as the muscles attached to it respond to stimuli such as light, which shrinks pupils. Darkness and stress...
Cyclogyl is the brand name of the generic drug, cyclopentolate ophthalmic. It relaxes the muscles in the eye, allowing the pupil to dilate. RXList reports that Cyclogyl is used by physicians to dilate the eye prior to examination or surgical...
The nervous system is crucial to the proper functioning of just about every part of the human body. Nerves carry messages that tell muscles to move, glands to excrete hormones, pupils to dilate and hearts to beat. Nerves tell the brain when the...
Eyes that remained fixed in one spot would severely limit your ability to take in the world around you. Fortunately, nerves transmit signals from the brain to the muscles attached to the eye to make them move up, down and sideways. Nerves also...
The pupil is the tiny dark hole in the center of the iris that dilates or constricts in response to the amount of light available and emotional states such as fear. The iris’s two muscles control the pupil’s size. Disorders that...
The human eye is a spherical organ that processes the images in front of us. The eye is simultaneously delicate and sturdy, composed of many different parts and points that work together to enable your vision. Remember to treat your eyes with care...
The functions of the eye are influenced by impulses from several nerves in the skull called cranial nerves. The optic nerve translates visual information from the retina into nerve impulses that the brain can interpret. The oculomotor nerve...
Autonomic neuropathy refers to the various symptoms that can occur when the function of an autonomic nerve is disrupted. The autonomic nerves perform such functions as regulating blood pressure, controlling digestion and enabling sexual function....
There are 12 cranial nerves that pass directly from the brain through openings in the skull. Each of these nerves serves a unique function: some provide sensory information to the brain; some allow messages to pass from the brain to muscles,...
Pseudoexfoliative glaucoma is a condition in which deposits of protein build up in the eyes. This can make it difficult for a liquid known as the aqueous humor to drain from the eyes, ultimately leading to increased eye pressure and nerve damage....
There are about 40 weeks between the first day of the last menstrual period and the birth of the baby. The mother's and baby's bodies undergo a vast array of changes during this time. The stages of pregnancy are often divided into three stages,...
Neurological problems in children often cause eye problems if the nerves that lead to the eyes or the part of the brain that controls eye movements are damaged or diseased. A vast number of problems can cause ocular symptoms, which can cause...
An ophthalmoscope is an instrument used by doctors, ophthalmologists and optometrists to view the inside of the eye, particularly the back, or fundus, of the eye. The ophthalmoscope uses a bright light, lenses and mirrors to magnify areas of the...
A cataract forms when the natural lens of the eye becomes cloudy because of age, trauma or disease. An ophthalmologist will suggest cataract surgery when the cataract interferes with a patient's vision. According to the Academy of Ophthalmology,...
Cocaine is a highly addictive drug that is illegal in the United States. According to Drugs.com, the powder form of cocaine can be snorted up the nose or rubbed on areas of the skin like the gums or genitals. The powder can also be mixed with...
The size of your pupils fluctuates dozens of time during the day in response to changing light. Assuming you're not exercising in the dark, some other factor is at play if your pupils are dilated during a workout. Dilated pupils should be low on...
Marijuana is an illegal but commonly used drug. Ten percent of Americans use marijuana regularly, according to the online medical encyclopedia MedlinePlus. Hashish, or "hash" is one form of marijuana; it is taken from the very tops of the female...
The iris is the colored muscle, called the sphincter muscle, of the eye that expands and contracts the pupil to control the amount of light entering the eye. In an eye that functions properly, the pupil will appear larger in low light and look...
During a regular health check-up, your health care provider may perform basic eye tests, such as asking you to read an eye chart, or he may look in your eyes with a hand-held scope. These basic eye checks may help detect significant vision changes...
During a full eye exam, most eye doctors need to dilate a patient's pupils. This allows him a clear view to see into the back of the eye. The doctor's assistant will put a drop in each eye, and the patient will wait a few minutes before the drops...
Dilating drops allow doctors a better view into the eye, make it easier to perform eye surgery, and relieve the pain of some eye diseases, like uveitis, an inflammation of the uvea in the eye. Drops used to dilate eyes are called mydriatics....
Acute angle closure is also known as acute glaucoma, or acute angle glaucoma. It occurs when the part of the eye called the anterior chamber angle becomes more narrow than usual; in extreme cases the anterior chamber angle closes completely. When...
Cymbalta is a prescription medication containing duloxetine hydrochloride. It is approved by the U.S Food and Drug Administration to treat major depression, fibromyalgia, generalized anxiety disorder and pain associated with diabetes. Cymbalta is...
Eye inflammation results from conditions that irritate the tissues in certain parts of the eye. For many people, inflammation will result in eye redness and discomfort. A person with severe symptoms may need to contact an eye doctor to determine...
Uveitis is an inflammation of the uveal tract in the eye. The uveal tract comprises the middle part of the eye, made up of the anterior and posterior chambers. The anterior chamber, which includes the iris, the colored portion of the eye, is more...
Sugar levels in the blood, or blood sugar, are regulated in the body by insulin. Learn about blood sugar, including treatments and safe levels, in this health video.
