About 5 to 10 percent of the American population struggles with farsightedness, per the National Eye Institute. Farsightedness is known as hyperopia, and it occurs when the eyeball is either too short or the cornea is too flat. Instead of light being focused directly on the retina, it focuses behind it, causing blurry vision for up-close objects.
Presbyopia is a form of farsightedness that occurs around age 40. The New York Times reports that nearly everyone will suffer from some degree of it by age 50.
Farsightedness is measured in diopters and is considered a "plus" refractive error. The higher the plus diopter, the more significant the level of farsightedness. (Learn More) You may be able to tell that you are struggling with presbyopia if you have trouble focusing on things up close, have to hold things farther away from your eyes to read them, struggle to read in low-light situations, or start to suffer from eye strain and headaches. (Learn More)
A true diagnosis of farsightedness requires an eye exam by an ophthalmologist who can measure your eyes, determine the level of the refractive error, and come up with a treatment plan. Farsightedness can be treated with glasses, contacts, or laser eye surgery. (Learn More) The level of farsightedness experienced will determine the type of treatment.
Mild to moderate farsightedness can be treated with LASIK (laser-assisted in-situ keratomileusis) or PRK (photorefractive keratectomy). Extreme farsightedness often requires an intraocular lens (IOL) implant or a refractive lens exchange (RLE) procedure. (Learn More)
Levels of Farsightedness
Farsightedness is measured in diopters, which is a unit of measurement dealing with optical power. When a person is farsighted, the diopter errors are classified as positive and written as +1 and so forth. The higher the number, the greater the level of farsightedness.
Generally speaking, mild to moderate farsightedness is measured between +2 and +4 or so. Anything over +5 is considered extreme farsightedness.
Farsightedness is caused when the cornea is flatter than it should be, and the light that is supposed to be focused on the retina is actually focused behind it. Farsightedness can also be caused by the eyeball being shorter than it should be.
With mild farsightedness, the eyes may be able to accommodate for the refractive error on their own, and you may not notice your vision being impacted at all. Children are often farsighted, but their eyes are able to make up for it. As the eyeballs grow, the refractive error lessens.
Mayo Clinic publishes that extreme farsightedness makes it difficult to see near things clearly, and you will only be able to see things far away in full focus. Milder farsightedness may make things appear blurry up close, but they will still be visible and even potentially discernible. In the case of extreme farsightedness, you may not be able to focus at all.
Presbyopia is a form of farsightedness that occurs due to age. As you age, the muscle fibers around the lens of the eye weaken, and the lens becomes more rigid, harder, and less flexible. This can make it harder to focus on things up close.
Presbyopia usually becomes noticeable around the mid-40s and can continue to progress up through the mid-60s. Presbyopia affects almost all people by middle age, as the lens is less able to change shape and constrict to focus on things close up. It can progress slowly over time and worsen with age.
Diagnosing Farsightedness and Presbyopia
You can tell if you are struggling with farsightedness or presbyopia if your vision is blurry, and you have trouble focusing clearly on things that are close. There are additional signs of farsightedness.
- Eye strain
- Trouble seeing clearly in dimly lit locations
- Needing to hold things away from your eyes to see better
- Difficulties reading books, newspapers, menus, or anything else up close
You will probably be able to self-diagnose presbyopia or farsightedness just by recognizing that things appear blurry up close. To determine the level of farsightedness that you suffer from and to get an official diagnosis, you will need a comprehensive exam from an ophthalmologist. Farsightedness can often be missed by an eye exam that includes reading letters off of a chart, as that only checks for myopia, or nearsightedness.
To check for farsightedness, your eyes will typically need to be dilated. The American Academy of Ophthalmology (AAO) explains that a special light will be shined in them, and a retinoscope is then used to measure how the light is reflected off the retina. Other specialized instruments, such as a phoropter, can be used to measure the level of the refractive error.
At the beginning stages of presbyopia and with mild farsightedness, you may be able to treat it with "readers" or reading glasses you can buy without a prescription. These can help to magnify the printed word so you can read better. With more significant levels of farsightedness, you may need prescription eyewear, such as contacts or eyeglasses, to help you see clearly up close.
If you also struggle with nearsightedness, you may need bifocals or multifocal lenses to correct both refractive errors. These specialized prescription contacts or glasses have two different prescriptions on them in different places on the lens, based on how you would be looking at things. For instance, the top part of the lens will correct for distance vision since you are generally looking up and out for that, and the lower part will correct for up-close refractive errors since you usually look down to read.
Additional treatments for farsightedness include corrective laser eye surgeries. Mild to moderate farsightedness can be treated with LASIK or PRK — that is, refractive errors that are less than +5 diopters. Refractive errors that are greater than +5 diopters usually cannot be corrected with LASIK or PRK. Instead, an intraocular lens (IOL) implant or a refractive lens exchange (RLE) may be needed.
LASIK and PRK use specialized lasers to cut a flap in the outer layer of the cornea. In the case of farsightedness, the cornea tissue underneath (the stroma) will be built up or "steepened." With LASIK, the flap is replaced after the procedure, while with PRK, it is usually discarded.
For presbyopia, monovision LASIK is an option that corrects each eye differently. They will no longer work together but can adjust to be able to see clearly both up close and far away.
The journal Review of Cornea and Contact Lenses publishes that clear lens exchange, RLE, and IOL implantation can offer new advances in technology and may be preferred over monovision LASIK for presbyopia. With RLE and IOL implants, the lens of the eye is replaced completely with an artificial lens.
Technological advances continue to be made, and there are many viable treatment options for presbyopia today. Your ophthalmologist can help you to decide what form of treatment will be the most effective for your level of farsightedness.
Facts About Hyperopia. (July 2016). National Eye Institute.
Training Your Brain So That You Don't Need Reading Glasses. (March 2017). The New York Times.
Farsightedness. (June 2018). Mayo Clinic.
Presbyopia. (December 2017). Mayo Clinic.
Farsightedness: Causes and Corrective Treatments. (April 2017). Medical News Today.
Farsightedness: Hyperopia Diagnosis. (March 2017). American Academy of Ophthalmology.
Presbyopia: The State of Surgical Correction. (March 2018). Review of Cornea & Contact Lenses.