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...
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....
Eye-dilating drops make it possible for a medical practitioner to examine the interior of the eye. While people often don't like getting them, it's impossible to do an adequate eye exam without them. Like all medications, dilating drops can cause...
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...
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...
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...
The pupil's size is determined by a balance between the input from the two parts of the autonomic nervous system --- sympathetic and parasympathetic. Sympathetic nerves release adrenaline, which causes the pupil to expand. Parasympathetic nerves...
Pets and kids can be a wonderful combination. Pets, which often become virtual members of the family, offer unconditional love and companionship, and can teach valuable lessons about commitment, nurturing, responsibility and reverence for life....
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....
Cataracts affect the lens of the eye. When a person has a cataract, the lens is obstructed by a cloudy mass that prevents him from seeing clearly, with her field of vision resembling a fogged window.
Dry, red eyes are characterized by sensation of stinging, burning or itching behind the eyelids or in the eyes. After watching TV or reading, the eyes may feel strained or tired, and become are red and dry. According to the University of Maryland...
The delicate skin under your eyes can be prone to appearing baggy or puffy because the skin is so thin there that the presence of fluid can appear pronounced. The blood vessels under the eyes are closer to the surface as well, and when dilated can...
Eye exams evaluate much more than your ability to distinguish a fuzzy letter 'O' from a fuzzy letter 'Q'; in many cases, they are crucial in detecting serious diseases. According to the American Optometric Association, a healthy adult should have...
With typical outputs of 10 to 20 lumen, flashlights pose little or no threat to the eyes. One reason for this is the built-in defense ability that the eyes possess. Through the coordinated efforts of the pupil, iris, retina and the optic nerve,...
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...
Maintaining healthy eyes and good vision requires routine eye examinations. Eye care professionals gather each patient's medical information, such as allergies to medications, to monitor eye health, but also to avoid complications from any part of...
Circles under the eyes cause many people concern. The Mayo Clinic states that dark circles can make a person feel old, tired and unhealthy. While each person may have a different definition of what constitutes an under eye circle, the Mayo Clinic...
If you regularly wake up in the morning with eyes that feel and/or look slightly swollen, you could be suffering from puffy morning eyes. This common occurrence can be the result of several contributing factors, including how you sleep---and how...
Dark eye circles can make you look haggard and tired, even when you've had a good night's sleep the night before. Genes are the ultimate determining factor when it comes to dark circles. The Mayo Clinic says broken capillaries, thin skin around...
Diabetes induced vision loss occurs in three ways: diabetic retinopathy, cataracts and glaucoma. Diabetic retinopathy is the consequence of damage to the blood vessels in the retina. Cataracts occur when the eye's lens clouds, producing blurred...
Glaucoma, the second-leading cause of blindness, is a group of eye disorders that slowly damage the optic nerve. During routine eye examinations, an optometrist checks for abnormal levels of intraocular pressure, which causes most cases of...
The eye pupil is the hole in the middle of the iris, the colored part of the eye. Pupils dilate and shrink in response to light; two muscles control pupil size, according to "Fundamentals for Ophthalmic Personnel." Pupillary reactions are...
When dark circles form under your eyes they can age you, or make you look tired and worn down, even if you are feeling fine. Dark under-eye circles can occur from the development of excess pigment below the eyes, or can be the shadow from puffy...
Dry, red, sore eyes can be both uncomfortable and irritating. Red eyes occur from dilated blood vessels in your eyes. Dry and sore eyes typically occur when your tear production isn't sufficient to moisturize your eyes. Your eyes may experience...
Retinoblastoma is a childhood cancer that occurs in the eyes of young children. Sometimes one eye is affected (unilateral retinoblastoma) and sometimes both eyes are affected (bilateral retinoblastoma). This rare eye cancer, which originates in...
Puffiness and dark undereye circles can cause you to look more tired and older than you are. Dark circles are caused by a number of factors, including genetic history, allergies, what you eat or drink, sun exposure and thinning skin. Puffy eyes...
Eye infections may result from different types of bacteria, viruses and fungi. They may cause discomfort, redness, swelling and irritation, but these symptoms may disappear without treatment. Some infections may require medication to prevent...
Glaucoma is elevated intraocular pressure (IOP) that squeezes the optic nerve fibers and causes vision loss. There are two types of glaucoma: open-angle and narrow-angle. In open-angle glaucoma, aqueous humor (fluid) drains freely through the...
Visual disorders are the result of an interruption of the processing of images through the cornea to the retina and optic nerve and then to the brain for interpretation. Congenital defects, injury and age affect the ability to see clearly. Eye...
Intraocular melanoma is a form of eye cancer that can be very deadly. Get expert tips and advice on preventing and treating eye cancer in this video.
Glaucoma is an eye disease that can lead to blindness. Get professional tips and advice on diagnosing, preventing, and treating glaucoma in this video.
Pink eye is an inflammation of the white of the eye sometimes caused by a virus or bacteria and sometimes by an allergic reaction. Get expert tips and advice on preventing, diagnosing, and treating pink eye in this video.