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AMBLYOPIA is reduced vision in an eye that has not received adequate use during early childhood.  It is the most common cause of vision problems in children.  Also referred to as “lazy eye”.   It is most often the result of misalignment of the eyes (crossed eyes) or one eye focusing better than the other.  Early diagnosis and treatment can often correct the difference and the sight in the “lazy eye” can be restored.


ASTIGMATISM is a common condition in which the cornea is abnormally curved, causing blurry vision.  Astigmatism can be corrected with glasses, contact lenses or surgery.


BIFOCALS are simply two lenses with different focal points placed into one single pair of glasses.  Bifocals are most commonly prescribed to people with presbyopia who also require a prescription for myopia, hyperopia, and/or astigmatism.


BLIND SPOT is the area where the optic nerve leaves the retina. A normal eye has a blind spot where there are no photoreceptor cells.


CATARACT is a cloudy area in the lens of the eye.  Cataracts occur when the natural lens inside the eye becomes discolored or cloudy, causing blurred or distorted vision. This blurring is the result of a chemical change within the eye, most often occurring after the age of 55. The direct cause of cataracts is not known, although heredity, injury, and/or disease might be factors.


CHALAZION is a lump in the eyelid caused by an obstruction of an oil gland.  While a chalazion can become red, warm or painful, it is not a stye.   A stye is caused by an acute infection of the gland.  The chalazion is an inflammation of the area, but is not an infection.  Some chalazion require surgical removal, others can be treated with warm compresses or anti-inflammatory medication.


CONJUNCTIVITIS is a common form of ocular infection in which the conjunctiva becomes inflamed or irritated.   Conjunctivitis can be caused by bacteria, viruses, allergies, or chemical irritants.  The most common form of conjunctivitis is called “pink eye” and is caused by contagious bacteria or viruses.  Symptoms to the eyes may include the following: red, swollen, inflamed, blurry and itchy.


CORNEA is the clear front window of the eye that transmits and focuses light into the eye.


CORNEAL EDEMA  is swelling of the cornea that occurs when the cornea is unable to keep itself  clear, and fluid begins to accumulate within it.  Corneal edema, when mild, may cause fluctuating or occasionally blurred vision.   It is most often worse when first opening the eyes after sleeping.  Treatment varies from over the counter remedies to surgery.


CORNEAL EROSION or abrasion can occur when the cornea is scraped or injured.  Such an injury may result in the loss of the outer layer of the cornea (epithelium).  Corneal erosion or abrasion usually is from a poke in the eye (from a fingernail, tree branch) or even from vigorous rubbing of the eye.  A visit to Dr. Oevermann  is recommended to detect and treat this condition since antibiotics are often prescribed to prevent infection.


DIABETIC RETINOPATHY is a complication of diabetes that is caused by changes in the blood vessels of the retina. When blood vessels in the retina are damaged, they may leak blood and grow fragile, resulting in brush-like branches and scar tissue. As a result, the images that the retina sends to the brain are blurred or distorted. The leading cause of blindness in the United States is diabetic eye diseases.  Fortunately, regular eye exams and proper follow-up can greatly reduce severe vision loss.


DIOPTER is a unit of refractive power.  An eyeglass prescription is commonly written with numbers that represent diopters. The higher the diopter measurement, the more vision correction that is needed.


DRUSEN are tiny white or yellow deposits in the retina of the eye or on the optic nerve head.  Drusen is common in aging eyes, with most people over the age of 40 having at least some drusen.  However, the presence of large amounts of drusen may be indicative of age-related macular degeneration.   Dr. Oevermann can detect drusen during a comprehensive eye exam.


DRY EYE can be caused by a number of factors:  weather, medications, age, contact lenses and temporary or chronic health conditions. Dry Eye occurs when the tear film is abnormal or the normal flow of tears over the eyes is interrupted.  Symptoms of dry eye may include the following:  burning/stinging, dryness, itching, sensitivity to light, scratchiness/grittiness and mattering (mucous secretions in the eye).


FARSIGHTEDNESS or hyperopia is caused because the eyeball is shorter than normal, causing light to be focused behind the retina instead of directly on it.  People with hyperopia have trouble seeing objects that are nearby.  Farsightedness is most often detected early in life.  Children can outgrow hyperopia as the eyeball grows longer.  However, some children do not outgrow hyperopia and corrective lenses are required.  If left untreated, children may develop crossed eyes (strabismus) or lazy eye (amblyopia).  Prescribing glasses at an early age often prevents these conditions.


FLASHES occur when the gel-like fluid (vitreous) pulls  or rubs on the retina.   You may have experienced this same sensation if you have ever been hit in the eye and have seen “stars”.    As we grow older, it is common to see flashes.  These flashes can appear off and on for several weeks or even months.  As such, not all flashes of light are serious, however, if you see sudden flashes of light, you should see Dr. Oevermann as soon as possible because it could indicate that the retina has been torn.


FLOATERS are small spots or “threads” in your field of vision.    Inside your eye, is a clear, gel-like fluid called the vitreous.  You may see floaters if some of the gel clumps together.  These clumps are seen as shadows by your retina.  Floaters can be seen as dots, threads, or cobwebs.  Floaters are a natural occurrence as we age, and are more bothersome than a cause for serious concern.  However, if a large number of floaters suddenly appear in your vision, or if they seem to worsen over time, you need to see Dr. Oevermann as soon as possible since this could be a sign of a more serious condition (retinal detachment).  Additionally, if  the floaters appear along with flashes of light or if you have any vision loss, you should seek immediate medical attention.


FUNDUS is the interior rear part of the eye.  It includes the retina, optic disc, macula, and blood vessels.  It includes the central region and the peripheral region of the eye.


GAS PERMEABLE CONTACT LENS are contact lenses made of a firm, durable plastic that allows oxygen to transfer through them.  Because they don’t contain water like soft lenses, they offer excellent eye health since they resist deposits and are less likely to harbor bacteria. Gas permeable lenses are custom made for each individual, and usually require an initial adaptation period.  Gas permeable lenses offer clearer vision due to the fact that they hold their shape better than soft lenses.


GLAUCOMA, OPEN ANGLE tends to develop quickly and without symptoms.   This is the most common type of glaucoma and affects roughly three million Americans.  Glaucoma happens when they eye’s drainage  canals become clogged over time.   As a result of the inadequate drainage, the inner eye pressure rises.  If left untreated, glaucoma can cause a gradual loss of vision.  Fortunately, if diagnosed early, this type of glaucoma usually responds well to medication.  Unfortunately, there is no cure for glaucoma and vision lost cannot be restored.   Early diagnosis and treatment is the best way to preserve your vision.


GLAUCOMA, CLOSED ANGLE is much more rare than open angle glaucoma.  The eye pressure tends to rise very quickly.  With this type of glaucoma, the iris is not as wide and open as it should be.  This type of glaucoma can usually be corrected with surgery to remove a portion of the outer edge of the iris.  This action helps to unblock the drainage canals so that the extra fluid can drain.  Surgery is usually successful and the effects long lasting. However, regular check-ups are still a must.  Symptoms may include eye pain, headaches,  rainbows around lights at night, very blurred vision and nausea.


HAAB’S STRIAE are horizontal breaks in the descemet’s membrane of the eye, which normally do not affect vision.  


HYPEROPIA (farsightedness) occurs when the eye is too short for the cornea’s curvature.  As a result, light rays entering the eye focus just behind the retina instead of on the retina.  A blurry image is produced.  A person with hyperopia cannot see distant objects clearly.    Farsightedness  is often present from birth, and most children outgrow the condition.  Glasses or contact lenses can correct the problem. Some symptoms may include the following:  aching eyes, blurred vision of close objects, crossed eyes in children, eye strain, headache while reading.


HYPERTENSION is a term used to describe high blood pressure.  It is caused when the systemic arterial  blood pressure is elevated.  High blood pressure can cause damage to many parts of the body, including the eyes. Hypertension can damage the tiny blood vessels that feed the retina, a condition called hypertensive retinopathy.  It is important to schedule regular exams with your primary care physician if you have hypertension or a family history of hypertension.  Regular eye exams are a good idea, even when your vision is fine.  Eye exams offer early detection of treatable eye problems and also provide a good opportunity to spot subtle changes  caused by other systemic conditions.


INTRAOCULAR PRESSURE is the measure of the  fluid pressure inside the eye. When drainage passages become blocked, the increased pressure can damage the optic nerve.  Damage to the optic nerve can permanently damage eyesight or even cause blindness.  Intraocular pressure can also be caused by the use of topical steroid drops used to treat other eye problems.  This is usually a temporary condition. Dr. Oevermann would detect intraocular pressure using a tonometer.


INTRARETINAL HEMORRHAGE is bleeding in the inner layers of the retina of the eye.


IRIS is the colored part of the eye. It is composed of two layers:  “stroma” or outer layer, which can be blue, hazel, brown or green and the back layer, which is always brown.   The iris acts a shutter to regulate the amount of light that reaches the retina.  The iris is responsible for controlling the size of the pupils, and as such, the amount of light that reaches the retina.

Blue Iris Color


KERATITIS is inflammation of the cornea, which is the outermost portion of the eye.  Keratitis is usually accompanied with conjunctivitis, pain and excessive tearing.  Patients with keratitis may experience photophobia (light sensitivity) and a reduction of vision.  Keratitis can be caused by bacteria or viral causes.  Contact lens wearers need to be diligent about cleaning their lenses since keratitis can be caused by bacteria on dirty lenses.


KERATOCONUS is a disorder that occurs when the cornea becomes cone-shaped.  The cornea, which is the front clear part of the eye, is usually rounded.  Keratoconus results in decreased vision due to the irregular shape of the cornea’s surface.  The progression is usually slow and can stop at any stage from mild to severe.  It is usually present in both eyes, but may be worse in one eye versus the other.

Cone-shaped cornea caused by Keratoconus.


LASIK is currently the most technologically advanced refractive surgical procedure to reduce or eliminate near-sightedness, far-sightedness, and astigmatism. The procedure involves reshaping the cornea with an extremely precise laser so that light entering the eye is correctly focused. Dr. Oevermann works with several LASIK surgeons and can assist each patient in choosing the best surgeon. All pre-operative and post-operative care is conveniently performed in our office.


LAZY EYE is an eye condition that has reduced vision that is not correctable by glasses or contact lenses and  is not caused by any eye disease.  It can result from failure to use both eyes together. Symptoms are not obvious, but may involve favoring one eye or a tendency to bump into objects on one side.  Early diagnosis and treatment increases the chance for a complete recovery.  Lazy eye will not go away on its own.  


LOW VISION is a condition where vision is not fully treatable by medical, surgical or conventional glasses or contact lenses (to at least 20/40 in one eye).  A thorough examination is required to determine the type of therapeutic treatment required.


MACULA is the small central portion of the retina that is located on the inside back layer of the eye.  The macula is responsible for clear, sharp vision.  Without a healthy macula, it is impossible to see vivid details and color.  This is due to the fact that the macula is the most sensitive part of the retina.


MACULAR DEGENERATION  is the leading cause of blindness (among older people) in the United States. It results from changes in the macula. There are two types of macular degeneration:  age-related, and a less common type, wet form macular degeneration.  With AMD, it is thought to be a normal part of the aging process in some people caused when the tissue of the macula thins and stops working well.  With the wet form, it is caused by fluids from newly formed blood vessels leak in the eye.  Early detection and prompt treatment is critical in limiting the damage caused by macular degeneration.


MACULAR EDEMA is a condition in which swelling develops in the macula (center region of the retina). This can be caused for many reasons, but most commonly from medications, certain inflammatory diseases or after eye surgery. Symptoms may include blurred or decreased central vision and painless retinal inflammation (usually after cataract surgery).  Fortunately, most patient recover their vision with proper treatment.  If you experience any of these symptoms, consult Dr. Oevermann right away.


MONOVISION is a treatment option prescribed for people over 40 who are affected by presbyopia, which occurs as a natural part of aging in which the  eye’s lens lose their ability to bring near objects in focus.   Monovision means wearing a contact lens for near vision in one eye, and if needed, a lens for distance in the other eye.


MYOPIA is also called nearsightedness and is a condition in which the visual images come to a focus in front of the retina of the eye.  It is a refractive error of the eye and patients with this condition have trouble seeing things at a distance. The exact cause of nearsightedness is not known. However, if both parents have myopia, there is an increased chance that their children will also have myopia.


NEARSIGHTEDNESS is also called myopia.  See above definition.


NEVUS, CONJUNCTIVAL is a freckle on the eye. These are typically present at birth and are normally benign.  Nevi can become enlarged with hormonal changes such as in puberty, pregnancy and with oral contraceptives.  May be occasionally difficult to distinguish from melanoma.  A biopsy should be performed for suspicious appearing lesions.


NIGHT BLINDNESS is the inability to see at night or in poor light.


OCULAR ALLERGIES cause inflammation of the eye membranes or conjunctiva.  There are many different types of ocular allergies including eczema, conjunctivitis and blepharitis.  Eyes are sensitive to soaps, cosmetics, detergents and airborne  allergens (like pollen or dust).  Symptoms may include redness, tearing, oozing, crusting, and itching.


OCULAR HYPERTENSION  has no noticeable signs or symptoms. Ocular hypertension is an increase in the pressure in your eyes that is considered above the normal range with no detectable changes in vision or damage to the structure of your eyes. It is common in people that have diabetes or are very nearsighted.  Not all people with ocular hypertension develop glaucoma, but there is an increased risk of developing glaucoma.  Regularly scheduled exams are critical to maintaining your overall eye health.


OPHTHALMOLOGIST is a medical doctor that specializes in vision and eye care.  An ophthalmologist specializes in the diagnosis and treatment of eye diseases.


OPTOMETRIST licensed by the Texas Optometry Board, a health care practitioner trained to diagnose signs of ocular, neurological and systemic health problems and treat vision disorders.


OD & OS  are abbreviations for the right (OD) and left (OS) eye.


PACHYMETER is a medical device that is used to measure the thickness of the cornea.  The pachymeter is often used to determine if a patient is a good candidate for LASIK, but is also helpful in monitoring the progression of certain disorders (measuring corneal changes).


PHOTOREFRACTIVE KERATECTOMY (PRK) is an alternative to LASIK.  It was originally approved by the FDA in 1995 and can be used to treat myopia, hyperopia and astigmatism. The procedure using laser pulses to reshape the cornea so that it can focus light more effectively.  A small portion of the epithelium (most superficial layer of the cornea) is removed and the laser is used to reshape the underlying cornea.  PRK may be offered for those patients whose corneal thickness or shape does not allow for LASIK to be performed.


POLARIZED LENS are lenses designed to reduce glare caused by reflections of water, snow and road surfaces.  These type of lenses filter the waves of light by absorbing some of the reflected glare while allowing other light waves to pass through them.


POSTERIOR VITREOUS DETACHMENT is the separation of the vitreous from the retina and is also known as PVD.   Most often occurs in middle age when the vitreous gel of the eye starts to thicken or shrink.  This action can cause clumps or strands to form in the eye.  Additionally, the vitreous starts to pull away from the back wall of the eye causing flashes.


PRESBYOPIA is the normal aging of the eye and its focusing ability  resulting in the inability to see clearly at close distances (reading, computer work).  Beginning in the mid-forties, most people begin to notice changes in their eyesight, especially their ability to see clearly at close distances.  A comprehensive eye exam is recommended at least every two years.


RADIAL KERATOTOMY (RK) is a surgical procedure performed to correct nearsightedness (myopia). It works by changing the shape of the cornea.  The procedure reduces or eliminates the need for corrective lenses, such as glasses or contact lenses. The procedure involves making precise incisions in the cornea.  These incisions cause the cornea to protrude, resulting in a flattening of the cornea.  As such, the focal point of the eye is closer to the retina.  This allows for an improvement in the patient’s distance vision.  Not everyone is a good candidate for RK surgery. It is most successful in patients that have a low to moderate amount of nearsightedness.    People with nearsightedness caused by keratoconus (nearsightedness caused by a cone shaped cornea), are not candidates for RK.  People under 18 years of age are also not usually good candidates for this procedure since their eyes are still growing and changing shape.  Additionally, women who are pregnant or have just given birth are not good candidates due to hormonal changes happening during this time.  People with glaucoma, any auto-immune disease that interferes with healing or uncontrolled diabetes should not have RK.  


REFRACTION a test for the eyes’ ability to focus light rays properly on the retina at near and far distances.  Refraction occurs when a light ray changes mediums.  The light rays will almost always bend when moving from one medium to another of varying density.


RETINA is the light-sensitive tissue lining the inner surface of the eye.  As light passes through the iris, it hits the retina and is converted to electrical signals and carried by the optic nerve to the brain.   

The retina is composed of two layers. The outer parts are responsible for our peripheral vision, while the center area, macula is responsible for fine central vision and color vision.


RETINAL DETACHMENT is an emergency situation when the retina detaches from the layer of blood vessels that provides it with oxygen and nutrients.  Since a retinal detachment deprives the retina of oxygen, it is critical to see a specialist right away.  The longer this condition remains untreated, the great the risk of permanent vision loss.  Fortunately, the symptoms of retinal detachment are usually noticeable and include the following:  spots or floaters (look like spots, hairs, strings) that seem to float before your eyes; sudden flashes of light in one or both eyes; a shadow or curtain over a portion of your visual field.


RETINOBLASTOMA is a rare type of eye cancer that usually develops in early childhood, typically before the age of five years old.   Even though it is rare, it is the most common form of cancer affecting they eyes in children.    Signs of retinoblastoma include the following:  white color in the center circle of the eye (pupil) when light is shone in the eye (camera flash); eyes that appear to be looking in different directions, eye redness and eye swelling.  


SCLERA is the “whites of your eyes”.   Sclera is the tough white, outer layer that covers  all of the eyeball except for the cornea.  The purpose of the sclera is to provide structure, strength and  protection to the eye.


SECONDARY CATARACT is a cataract that forms after cataract removal surgery.  These types of cataracts usually occur when a piece of the original cataract remains or scar tissue forms. Symptoms include blurring in a portion of your vision that should otherwise be clear after surgery.  It is very common, and fortunately, can be easily treated with a simple laser procedure.


STRABISMUS is also referred to as “crossed eyes” and is a disorder in which the eyes do not line up in the same direction.    As a result, the eyes do not look at the same place at the same time.  It is usually caused by poor muscle control or a high amount of farsightedness and occurs when the eye turns in, out, up or down.


STYE is an infection of the glands located along the eyelid.  The infection causes a small lump that is usually harmless, but causes tenderness, pain, redness and sometimes light-sensitivity and tearing.  A stye is often caused by a bacterial infection, but can also be caused by a clogging of the oil glands around the eyelashes or inside the eyelid.


TONOGRAPHY is the continuous measurement of intraocular pressure to determine the facility of aqueous flow.  It is used to determine the presence of glaucoma.


TRIFOCALS lens that requires three separate prescriptions.  This type of lens allows for vision at three different intervals:  near,  intermediate (arms-length) and distance vision.  Similar to bifocals, but with an additional segment for intermediate vision (located above the reading section).


UVEITIS is the inflammation of the uvea, which is the layer between the retina and the white of the eye (sclera).  The exact cause of uveitis is often unknown, but it can be caused by infections, injury, and autoimmune disorders. Click here for more information on this condition.


VERNAL CONJUNCTIVITIS is an allergic reaction that occurs during the warm weather months. Symptoms may include the following:  thick discharge, severe itching, white spots or ulcers on the cornea.  See Dr. Oevermann if you are experiencing any of these symptoms and he will determine the proper treatment (usually antihistamines to reduce itching and discharge).


VISION THERAPY is  an individualized treatment program designed to improve certain types of vision problems that cannot be corrected with glasses or contact lenses.  Used to improve a patient’s visual perception and coordination.


VISUAL ACUITY is the measure of how well a person sees or the clarity (clearness) of one’s vision.  20/20 vision is used to describe normal visual acuity measured at a distance of twenty feet. However, 20/20 does not necessarily mean perfect vision. This is only a measure of how clear the vision is at a distance.  20/100 means that you must be as close as 20 feet to see what a person with normal vision can see at 100 feet.


VISUAL FIELD refers to the total area in which objects can be seen peripherally (on the side) while you focus your eyes on a central point.  It is the area visible to the eye in a specific position.


VITREOUS DETACHMENT can occur with aging and happens when the vitreous gel separates from the retina.  This might not be a cause for concern, but can be, if it leads to retinal tears.  These tears can ultimately lead to retinal detachment.  As such, vitreous detachments are monitored closely.  You should see Dr. Oevermann if you see a sudden increase in floaters or flashes of light.