A complete eye exam is more than just updating your prescription for glasses or contacts. Your eye examination by an ophthalmologist consists of a series of tests to assess the overall health of your eyes. Your doctor also checks for eye conditions such as glaucoma, cataract, diabetes, hypertension, retinal detachments, etc.
It depends on the patient. A young, healthy person with no apparent problems will take about 20 minutes. Someone older, perhaps with high blood pressure, diabetes, glaucoma or other ailments can take much longer. Your eye doctor will determine what tests are needed to provide the correct information for new glasses or contact lenses.
It is a measurement of sight. “20/20” vision refers to 8.7mm tall letter that a person with “average” or “normal” vision can see at 20 feet. Someone with 20/40 vision can only be 20 feet away from an object to see what a person with normal vision can see at 40 feet. Similarly, the person with 20/400 vision can only be 20 feet away from an object to see what a person with 20/20 vision can see at 400 feet. Most states require 20/40 or better in at least one eye to get a driver’s license without glasses or contact lens restriction. Note that the term “20/20” does not reveal the quality of vision.
Refraction is the process of measuring your best corrected vision through various lenses. This measurement is part science and part art and utilizes a number of objective and subjective testing methods. It is common to have slightly different measurements in your refraction depending on factors such as examiner, type of tests used, time of the day, lighting conditions, and the use of dilating drops.
Anisometropia is a condition where there is a significant difference in the refractive errors of the two eyes. If this condition is present in infancy and is undetected or untreated, it often results in the development of lazy eye or amblyopia in the weaker eye. The greater the amount of the difference, the more likely the development of lazy eye will be. Another problem can occur when glasses are made for an anisometropic individual. The difference in the powers of the lenses induces a prismatic difference that can cause double vision in off-center areas of the lens, which can be compensated for by the use of slab-off prism.
This refers to the best vision that your eyes are capable of seeing with the best corrective glasses and / or contact lenses. It is generally a reflection of the health of the eyes such as with nearsightedness,farsightedness, or astigmatism. Best corrected vision is measured on the same eye chart as the visual acuity without correction.
Yes. Diabetes can cause severe problems with your sight. It is very important that your eyes are checked every year, preferably with drops to dilate the pupil, so that the retina (back of the eye) can be examined thoroughly.
It depends on your age. Annual comprehensive eye examinations are recommended for adults, contact lens wearers and children starting as early as age two. It is very important that children be examined before preschool since a visual condition could exist that could eventually impair a child’s vision if not detected early and treated. In addition to routine eye exams, you should have your eyes examined by an ophthalmologist if you have:
Decreased vision, even if temporary
New floaters (black “strings” or specks in the vision)
Parents should have their children’s eyes checked at three important stages during their early development: (1) when the infant is about 6 month old. A pediatric ophthalmologist makes sure that the eyes are working well together and there are no rarely occurring but significant defects, such as cataracts and tumors that could threaten the child’s vision; (2) between the ages of 2 and 3, before a child enters preschool. A pediatric/general ophthalmologist at this time checks for any signs of developmental disorders, including lazy eye, crossed eyes (strabismus), nearsightedness, farsightedness, and astigmatism. If a problem is found, effective therapy can usually begin immediately; (3) between the ages of 5 and 6, before the child enters kindergarten. Eye doctor now tests for sharpness of vision and corrects deficiencies by prescribing eyeglasses. A child’s eyes finish developing by the age of 8-9 years.
Early detection of eye problems can sometimes prevent significant damage to the eye or to vision. If any member of your family has eye problems, then it is important to have your child’s eyes tested at an early age.
Night blindness is more appropriately called as “impaired dark adaptation.” People with night blindness see poorly in the darkness but see normally when adequate amounts of light are present. The condition does not actually involve true blindness, even at night.
Color blindness, more accurately called color deficiency, is a term used for a deficiency in recognizing certain colors. Most color perception defects are for red or green or both. Another form of color blindness; yellow-blue is the second most common form, but it is rare and could be a result of some optic nerve disease. Complete color deficiency, where all colors are seen as varying shades of black and white is almost unknown. About 10% of males have a color perception defect, but this is rare in females.
Color deficiency is a sex linked character. Females are either not affected or they are the carriers with a normal vision. The males within the same family are affected. There is only a 50/50 chance that sons of carrier mothers will have altered color vision.
A female can inherit defective color vision gene either from her color deficient father or her carrier mother. Since the pattern of inheritance is known, future generations of color blind individuals can be easily predicted.
Color Vision deficiency could be acquired too. Certain drugs prescribed for arthritis, depression, heart disease, high blood pressure, diabetes, multiple sclerosis, and some liver diseases can significantly affect color vision either temporarily or permanently. Continued use of aspirin can also alter color perception. Excessive use of tobacco and alcohol can have similar effects. Many industrial chemicals can permanently alter your color vision.
Certain eye diseases such as glaucoma, cataract and most eye problems affecting the retina or nerve pathways to the brain can give gradually impair your appreciation for colors. Overall blurring of near or distance vision, or gaps in the field of vision may also alter color vision perception.
Since color vision changes can be an early sign of a disease or a side effect of prescribed medication, it is important that you consult an ophthalmologist if you are experiencing any changes in your color vision. It is noteworthy that unlike inherited color deficiency, both men and women are at equal risk for the acquired color vision problems and only one eye is affected at a time.
It depends upon the kind of job you do. Certain jobs, such as printing inks, textiles, and paints etc. require a precise perception of color. Because of your limited ability to recognize colors accurately, your performance at these jobs may be affected.
Generally, color deficient people are not denied a driving license. However, remember that a person with color blindness may drive through a red traffic light and cause a fatal accident. Driving laws in certain places are more strict and may limit color blind people from driving heavy commercial machinery.
Possibly yes. Colored objects are frequently used in teaching and learning processes. If you know that your child has difficulty in identifying certain colors, it will be a good idea to inform your child’s teachers accordingly.
No, there are no treatments available to correct your inherited color vision problems. Nothing can be done to replace a defective mechanism in your retina. Many color defective people learn how to compensate for this defect in their vision. It is important that good lighting is always available. Many people find limited help in identifying certain colors with the help of a small red or red-mauve filter held in front of the eye.
Schedule a comprehensive eye exam with an ophthalmologist. There are simple in-office tests that can screen for defective color vision. These tests typically involve reading colored numbers from a book or arranging colored papers in order or naming colored lights.
You are legally blind when the best corrected central acuity is less than 20/200 in your better eye, or your side vision is narrowed to 20 degrees or less in your better eye. Even if you are legally blind, you may still have some useful vision.
If neither of your eyes can see better than 20/60 without improvement from glasses or contacts, you may be defined as visually impaired. In addition, poor night vision, limited side vision, double vision and loss of vision in one eye may also determine visual impairment.
Low vision is a term describing a level of vision below normal (20/70 or worse) that cannot be corrected with conventional glasses. Low vision is not the same as blindness. People with low vision can use their sight. However, low vision may interfere with the performance of daily activities, such as reading or driving.
There is no predetermined schedule for changing glasses or contacts. It is necessary to check your prescription when it no longer provides adequate correction. However, it is a good idea to have regular eye exams.
Typically a person’s vision will fluctuate from birth through childhood and up to approximately eighteen years of age before it stabilizes. At forty years of age, difficulty with near vision will occur and continue to progress up to approximately sixty years of age.
Many people use the computer 8 or more hours every day. There is no way to eliminate eye fatigue, but we can check for several conditions that may be making your eye strain problems worse. Uncorrected hyperopia(farsightedness) and / or astigmatism may contribute to eye fatigue. Also, if you are in your forties, you may be experiencing a focusing problem called presbyopia. Dry eyes can also make the eyes feel more tired when doing extended computer work. Glasses that correct farsightedness, astigmatism, and presbyopia may allow you to use the computer with less eyestrain and more comfort.
If you find out that your arms are not long enough to look at the book or newspaper text and you are nearing forty, you may be ready for reading glasses. You’re not alone. This loss of focusing ability can start as early as 35 or as late as 50. It usually stops progressing at about age 60.
By age 45, almost everyone notices a decline in close vision. While some people may choose to go without eyeglasses if their lifestyle doesn’t require a lot of reading, that solution doesn’t work for most people. When you begin to notice problem in reading clearly, you should have your eyes examined.
If you’ve had your eyes checked and they are as good as you think, then your doctor will have no objection to you having plain or tinted lenses in a frame of your choice, or contact lenses that can enhance or change the color of your eyes.
Children have a much better ability to focus close at a younger age than adults. They get a much bigger picture at this distance. In general viewing anything close will not have any effect on physically changing the eyes on anyone. However, get your child’s vision tested by an eye doctor to make sure that he / she does not have a problem seeing far objects clearly.
No. Glasses and contact lenses allow you to see comfortably. When you remove them, you see less comfortably. This contrast is what makes some people believe their vision is worse for wearing glasses. Corrective lenses won’t make your vision problems go away, nor will they worsen them. They only correct the symptoms.
Yes! “Snow blindness” and a welder’s flash are examples of “sun burned” eyes. Outdoor enthusiasts and those with sensitive eyes should always wear sunglasses with an ultraviolet filter to block harmful UV radiation from the sun. Contact lens wearers are especially sensitive to bright light. You should always wear a good pair of non-prescription sunglasses with the contacts when outside.