At the ophthalmologist's office, the doctor will test your eyes, so as to evaluate the state of your vision, in addition, they will also run checks to see if any eye disease is present such as cataracts, glaucoma, macular degeneration, diabetic retinopathy, corneal abrasions.
In preparation for your visit, bring your glasses or contact lenses with you. Contact lenses must be removed for tests that use fluorescein, an orange dye that may dye your contact lenses if the lenses remain in your eyes. Remember to take with you a list of the oral medications and prescription eye drops that you are using as well.
Before seeing the doctor, you will be asked to fill out forms in regard to your medical and ocular history. Some offices have technicians that assist the doctor. The technician will ask you questions such as: Are you experiencing any eye problems?
Have you had any eye problems in the past? Do you wear glasses or contacts and are you having any problems with them? What health problems do you have now and in the past? What medications are you currently using? Do you have any allergies? Does any member of your family have eye problems, diabetes, high blood pressure, heart disease or other health problems? You should tell the ophthalmologist about your hobbies and work conditions. A computer user, for example, might need glasses to see the computer screen. If you use a computer and have blurry vision, sore and tired eyes, and neck and shoulder pain, you might have computer eyestrain and you may need special glasses.
Your vision will be tested using a standardized chart. Each eye is tested separately with and without the current prescription. One eye is covered while the other one reads the chart. The doctor also will check for the "best corrected vision" while you are wearing your glasses and are reading the eye chart. Your visual acuity is expressed in a fraction. The top number is your distance from the eye chart. The bottom number is the distance at which a person with normal eyesight could correctly read the line you read. 20/20 vision means that you see objects clearly from 20 feet away that someone who has normal vision could see clearly from 20 feet away.
The larger the denominator, the worse your visual acuity. If you cannot read any of the lines, a gross estimate of what you are able to see will be measured (e.g., can you detect light, motion or the number of fingers held in front of you). Your visual acuity at near will also be tested.
You will be instructed to look at the eye chart holding an instrument with pinholes. Pinholes only allow the passage of light perpendicular to the lens. The light is not bent before being focused onto your retina. If your visual deficit is corrected when you look through the pinholes, then the acuity issue is due to a refractive problem. If the deficit is not corrected, there is another reason that explains why you are visual problems.
If the doctor determines from the visual acuity test that you need glasses or contact lenses, he will go ahead with a refraction assessment. Refraction refers to how light waves are bent when they go through the cornea and the lens. Your ophthalmologist may use a computerized refractor to measure your eyes and estimate your prescription. He may use shine a light into your eye and evaluate the movement of the light that is reflected by your retina. You will be asked to look through a Phoroptor, a device that has wheels of different lenses. The doctor will ask you to tell him which combination of lenses gives you the sharpest vision. Observation of the External Structures
The ophthalmologist will use a slit lamp to see the structures at the front of your eye you will be asked to place your head on a chinrest. The slit lamp uses an intense line of light to illuminate your eye. The doctor will examine the cornea, iris, lens and the anterior chamber. Your doctor may use an orange dye called fluorescein to see your cornea and whether you have any abrasions, tears or infections.
The ophthalmologist will determine whether any muscles that control eye movement are weak. You will be asked to follow the doctor's index finger with your eyes only as the doctor moves it in different directions. The ophthalmologist will examine your eyes to see whether both eyes move and work as a team. People who have problems with binocular vision and eye teaming skills may have convergence insufficiency and poor depth perception.
The ophthalmologist will look at both eyelids to see if they cover approximately the same amount of eyeball. Damage to the nerves controlling these structures can cause the lids on one side to appear lower then the other.
Do the eyes maintain clear vision at varying distances? Problems with eye focusing usually result in visual fatigue and reduced reading comprehension. A person may avoid doing close work or other activities.
The ophthalmologist will check your pupil's response to light. You will look towards a distant area in the room while keeping your eyes open. The doctor will look through an ophthalmoscope. Diseases which raise intracranial pressure (e.g. brain tumors) may result in dilation of the pupils and unresponsiveness to direct stimulation by light.
The ophthalmologist will perform a 5 to 10 minute retinal examination, called ophthalmoscopy or fundoscopy. He will examine the back of your eye including your retina, optic disc, choroids and blood vessels. The retinal examination enables the doctor to detect eye diseases.
There are systemic diseases such as hypertension, diabetes and arteriosclerosis that affect vessels of this size. Based on the ophthalmologist's examination, he can make a guess as to what is happening in your body. The ophthalmologist uses eye drops which dilate your pupils and give you blurry vision. After your pupils are fully dilated, the doctor may shine a beam of light through your pupil and use an ophthalmoscope.
After the retinal examination, you might see afterimages. Another method that the doctor may use is examining each eye with a very bright light mounted on his forehead. The doctor may use the slit lamp along with the ophthalmoscope to look at the back of your eye. Some ophthalmologists now are using the Optomap. This machine enables the doctor to see more of your retina than observed during dilated exams.
The purpose of measuring your eye pressure is to determine whether you have glaucoma, a disease which causes pressure to build up inside your eyes and may result in blindness. If glaucoma is caught early, there is treatment. Before measuring your eye pressure, the doctor will place an anesthetic drop into your eye. Shortly thereafter, the surface of your eye will be numb and the doctor will place a tonometer gently against the surface of the eye. It is a painless procedure. Sometimes, noncontact tonometry is used with an "air puff" tonometer. This method can be less accurate but the advantage is that anesthetic eye drops are not used. It's a painless procedure.
Your eye doctor uses this test to determine whether you have difficulty seeing in any areas of your peripheral vision "the areas on the side of your visual field". A few different tests can assess your visual field: In the confrontation visual field exam, your eye doctor sits directly in front of you and asks you to cover one eye and look directly at him while he moves his hand in and out of your visual field. You tell him when you can see his hand. With the tangent screen exam, you sit a short distance from a screen and stare at a target at its center. You report when you can see an object move into your peripheral vision. Your doctor may use a computer program that flashes small lights as you look into a special instrument. You press a button when you see the lights. A map of your peripheral vision is made. Your ophthalmologist will use a map of the areas that you do not see to help diagnose your eye problem.
At the conclusion of the eye examination, the ophthalmologist will make a final diagnosis and discuss a treatment plan. You will be told when to return for your next visit.
Regular examinations are important because the sooner your vision problem is detected, the greater your chance of successful treatment.
If you don't wear glasses or contacts, have no symptoms, no family history of eye disease and no chronic disease, such as diabetes which can effect eyesight, have an eye exam at the following intervals: Once between ages 20 and 29, twice between ages 30 and 39, every 2-4 years between ages 40 and 65 and every 1-2 years after age 65. If you wear glasses or contacts, go for yearly exams. If you have other health problems or a history of eye disease in your family, you may need more frequent eye examinations.
Note that as we get older, there is an increased risk of developing more serious eye problems which can lead to a partial or complete loss of your vision. If you notice any problems with your eyes, make an appointment with your eye doctor as soon as possible. Remember, eyesight is precious and should not be neglected.