A single copy of this article may be reprinted for personal, noncommercial use only.
FarsightednessBy Mayo Clinic staff
Original Article: http://www.mayoclinic.com/health/farsightedness/DS00527
Farsightedness (hyperopia) is a common vision condition in which you can see distant objects clearly, but objects nearby may be blurry.
The degree of your farsightedness determines your focusing ability. People with severe farsightedness may see clearly only objects a great distance away, while those with mild farsightedness may be able to clearly see objects that are closer.
Farsightedness usually is present at birth and tends to run in families. You can easily correct this condition with eyeglasses or contact lenses. Another treatment option is surgery.
Farsightedness may mean:
- Nearby objects may appear blurry
- You need to squint to see clearly
- You have eyestrain, including burning eyes, and aching in or around the eyes
- You experience general eye discomfort or a headache after a prolonged interval of doing close tasks, such as reading, writing, computer work or drawing
When to see a doctor
If your degree of farsightedness is pronounced enough that you can't perform a task as well as you wish, or if your quality of vision detracts from your enjoyment of activities, see an eye doctor. He or she can determine the degree of your farsightedness and advise you of options to correct your vision.
Since it may not always be readily apparent that you're having trouble with your vision, the American Academy of Ophthalmology recommends the following intervals for regular eye exams:
If you don't wear glasses or contacts, have no symptoms of eye trouble and are at a low risk of developing eye diseases, such as glaucoma, it's recommended that you have a baseline eye exam around age 40, and then at the following intervals.
- Every two to four years between 40 and 54 years
- Every one to three years between 55 and 64 years
- Every one to two years beginning at age 65
If you're at high risk of certain eye diseases, such as glaucoma, the frequency of visits should be increased to:
- Every two to four years up to age 40
- Every one to three years between 40 and 54 years
- Every one to two years from age 55 onward
If you wear glasses or contacts, you'll likely need to have your eyes checked every year. Ask your eye doctor how frequently you need to schedule your appointments. But, if you notice any problems with your vision, schedule an appointment with your eye doctor as soon as possible, even if you've recently had an eye exam. Blurred vision, for example, may suggest you need a prescription change, or it could be a sign of another problem.
Children and adolescents
Children need to be screened for eye disease and have their vision tested by a pediatrician, an ophthalmologist or another trained screener during the newborn period, and then at every routine health exam throughout early childhood.
Additionally, it's recommended that school-age children be screened at school or through community programs approximately every two years to check for vision problems.
Your eye has two parts that focus images:
- The cornea, the clear front surface of your eye
- The lens, a clear structure inside your eye that changes shape to help focus objects
In a perfectly shaped eye, each of these focusing elements has a perfectly smooth curvature like the surface of a rubber ball. A cornea and lens with such curvature bend (refract) all incoming light in such a way as to make a sharply focused image directly on the retina, at the back of your eye.
A refractive error
However, if your cornea or lens isn't evenly and smoothly curved, light rays aren't bent (refracted) properly, and you have a refractive error. Farsightedness is one type of refractive error.
Farsightedness occurs when your cornea is curved too little or your eye is shorter than normal. Instead of being focused precisely on your retina, light is focused behind your retina, resulting in a blurry appearance for close-up objects.
Other refractive errors
In addition to farsightedness, other refractive errors include:
- Nearsightedness (myopia). This occurs when your cornea is curved too much or your eye is longer than normal, which makes faraway objects blurry and close objects clear.
- Astigmatism. This occurs when your cornea or lens is curved more steeply in one direction than in another. Uncorrected astigmatism blurs your vision.
Farsightedness can be associated with several problems, such as:
- Crossed eyes. Some children with farsightedness may develop crossed eyes. Specially designed eyeglasses that correct for part or all of the farsightedness may effectively treat this problem.
- Reduced quality of life. Uncorrected farsightedness can affect your quality of life. You might not be able to perform a task as well as you wish, and your limited vision may detract from your enjoyment of day-to-day activities. In children, untreated farsightedness may cause learning problems.
- Eyestrain. Uncorrected farsightedness may cause you to squint or strain your eyes to maintain focus. This can lead to eyestrain and headaches.
- Impaired safety. For your own safety and that of others, don't drive or operate heavy equipment if you have an uncorrected vision problem.
Preparing for your appointment
Three kinds of eye specialists, each with different training and experience, can provide routine eye care:
- Ophthalmologists. An ophthalmologist is an eye specialist with a doctor of medicine (M.D.) or doctor of osteopathy (D.O.) degree who provides full eye care, including performing complete eye evaluations, prescribing corrective lenses, diagnosing and treating common and complex eye disorders, and performing eye surgery when it's necessary.
- Optometrists. An optometrist has a doctor of optometry (O.D.) degree. Optometrists are trained to evaluate vision, prescribe corrective lenses and diagnose common eye disorders.
- Opticians. An optician is an eye specialist who fills prescriptions for eyeglasses — assembling, fitting and selling them. In some states, opticians are also allowed to sell and fit contact lenses.
No matter which type of eye specialist you choose, here's some information to help you get ready for your appointment, and know what to expect from your doctor.
What you can do
- If you already wear glasses, bring them with you to your appointment. Your doctor has a device that tells him or her what type of prescription you have now. If you wear contacts, bring an empty contact lens box from each type of contact you use to your appointment.
- Write down any symptoms you're experiencing, such as trouble reading up close or difficulty with night driving.
- Make a list of all medications, vitamins and supplements that you're taking.
- Write down questions to ask your doctor.
Your time with your doctor may be limited, so preparing a list of questions can help you make the most of your time together. For farsightedness, some basic questions to ask your doctor include:
- When do I need to use corrective lenses?
- What are benefits and drawbacks to glasses?
- What are benefits and drawbacks to contacts?
- How often do you recommend that I have my eyes examined?
- Are more permanent treatments, such as eye surgery, an option for me?
- What types of side effects are possible from eye surgery?
- Will my insurance company pay for the cost of eye surgery?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:
- When did you first begin experiencing symptoms?
- How severe are your symptoms?
- Does your vision improve if you squint or move objects closer (or farther) away?
- Do others in your family use corrective lenses? Do you know how old they were when they first began having trouble with their vision?
- When did you first begin wearing glasses or contacts?
- Do you have any serious medical problems, such as diabetes?
- Have you started to take any new medications, supplements or herbal preparations?
Tests and diagnosis
Farsightedness is diagnosed by a basic eye exam. A complete eye examination involves a series of tests. Your eye doctor may use odd-looking instruments, aim bright lights directly at your eyes and request that you look through an array of lenses. Each test allows your doctor to examine a different aspect of your eyes, including your vision.
Treatments and drugs
The goal of treating farsightedness is to help to focus light on the retina through the use of corrective lenses or refractive surgery.
In young people, treatment isn't always necessary because the lenses of their eyes are flexible enough to compensate for the condition. But as you age, the lenses become less flexible and eventually you'll probably need corrective lenses to improve your near vision.
Wearing corrective lenses treats farsightedness by counteracting the decreased curvature of your cornea or the smaller size (length) of your eye. Types of corrective lenses include:
- Eyeglasses. The variety of eyeglasses is wide and includes bifocals, trifocals and reading lenses.
- Contact lenses. A wide variety of contact lenses are available — hard, soft, extended wear, disposable, rigid gas permeable and bifocal. Ask your eye doctor about the pros and cons of contact lenses and what might be best for you.
If you're also having age-related trouble with close vision (presbyopia), monovision contact lenses may be an option for you. With monovision contacts, you may not need correction for the eye you use for distance vision (usually the dominant eye), but a contact lens can be used for close-up vision in your other eye. Some people have trouble adapting to this kind of vision because 3-D vision is sacrificed in order to be able to see both nearby and in the distance clearly. Monovision contacts can be worn intermittently as desired.
Modified monovision contact lenses are another option. With this type of contact lenses, you can wear a bifocal contact lens in your nondominant eye and a contact lens prescribed for distance in your dominant eye. You can then use both eyes for distance and one eye for seeing objects nearby.
Although most refractive surgical procedures are used to treat nearsightedness, they can also be used for farsightedness. These surgical treatments correct farsightedness by reshaping the curvature of your cornea. Refractive surgery methods include:
- Laser-assisted in-situ keratomileusis (LASIK). LASIK is a procedure in which an ophthalmologist makes a thin, circular hinged flap cut into your cornea. Then, your eye surgeon uses a type of laser called an excimer laser to remove layers from the center of your cornea to steepen its domed shape. An excimer laser differs from other lasers in that it doesn't produce heat. After the excimer laser is used, the thin corneal flap is repositioned.
- Laser-assisted subepithelial keratectomy (LASEK). Instead of creating a flap in the cornea, the surgeon creates a flap involving only the cornea's thin protective cover (epithelium). Your surgeon will use an excimer laser to reshape the cornea's outer layers and steepen its curvature and then reposition the epithelial flap. To facilitate healing, a bandage contact lens may be worn for several days after the procedure.
- Photorefractive keratectomy (PRK). This procedure is similar to LASEK, except the surgeon removes the epithelium. It will grow back naturally, conforming to your cornea's new shape. Like the LASEK procedure, PRK may require the use of a bandage contact lens for a few days following surgery.
- Conductive keratoplasty (CK). This procedure uses radiofrequency energy to apply heat to tiny spots around the cornea. The effect resembles plastic wrap being stretched by heat. The degree of change in the curvature of the cornea depends on the number and spacing of the spots as well as the way in which the cornea heals after treatment. The results of CK aren't permanent.
Some of the possible complications that can occur after refractive surgery include:
- Undercorrection or overcorrection of your initial problem
- Visual side effects, such as a halo or starburst appearing around lights
- Dry eye
- Rarely, vision loss
Discuss the potential risks and benefits of these procedures with your eye doctor.
Although you can't prevent farsightedness, you can help protect your eyes and your vision. Follow these steps:
- Have your eyes checked. Regardless of how well you see, have your eyes checked regularly.
- Control chronic health conditions. Certain conditions, such as diabetes and high blood pressure, can affect your vision if you don't receive proper treatment.
- Recognize symptoms. Sudden loss of vision in one eye, sudden hazy or blurred vision, flashes of light, black spots, or halos or rainbows around lights may signal a serious medical problem, such as acute glaucoma, a stroke or some other treatable retinal condition such as retinal tear or detachment. Seek immediate medical care if you experience any of these signs or symptoms.
- Protect your eyes from the sun. Wear sunglasses that block ultraviolet (UV) radiation. This is especially important if you spend long hours in the sun or are taking a prescription medication that increases your sensitivity to UV radiation.
- Eat healthy foods. Maintain a healthy diet that contains plenty of fruits and vegetables. A diet containing these foods has been associated with a decreased incidence of macular degeneration. Eat dark leafy foods and bright-colored fruits and vegetables, such as spinach, kale, carrots, yams and cantaloupe.
- Don't smoke. Just as smoking isn't good for the rest of your body, it can adversely affect your eye health as well.
- Use the right glasses. The right glasses optimize your vision. Having regular exams will ensure that your eyeglass prescription is correct.
- Use good lighting. Turning up the lights can improve contrast and help you see better.
- Bower KS. Laser refractive surgery. http://www.uptodate.com/index. Accessed Feb. 25, 2012.
- Care of the patient with hyperopia. St. Louis, Mo.: American Optometric Association. http://www.aoa.org/documents/CPG-16.pdf. Accessed Feb. 22, 2012.
- Preferred practice patterns: Refractive errors and refractive surgery. American Academy of Ophthalmology. http://one.aao.org/CE/PracticeGuidelines/PPP_Content.aspx?cid=e6930284-2c41-48d5-afd2-631dec586286. Accessed Feb. 25, 2012.
- Refractive error. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/print/sec09/ch099/ch099a.html. Accessed Feb. 22, 2012.
- Frequency of ocular examinations. American Academy of Ophthalmology. http://one.aao.org/CE/PracticeGuidelines/ClinicalStatements_Content.aspx?cid=810eaf61-181e-41c8-a0e8-e1d122efe5a4. Accessed Feb. 25, 2012.
- Opticians, dispensing. U.S. Department of Labor. http://www.bls.gov/oco/ocos098.htm. Accessed Feb. 25, 2012.
- Eye health tips. National Eye Institute. http://www.nei.nih.gov/healthyeyes/eyehealthtips.asp. Accessed Feb. 25, 2012.