Farsightedness, also known as hyperopia, is a common vision condition where distant objects are usually seen clearly, but close ones don’t come into proper focus. The term farsighted comes from “far” and “sighted” – farsighted people can see far away objects more clearly than near ones. This is caused by the eyeball being too short or the cornea having too little curvature, so light entering the eye isn’t properly focused by the time it reaches the retina. Mild farsightedness may not cause major issues for some people. But more severe forms can significantly impact daily life by making it difficult to perform close up tasks. This article will discuss what level of farsightedness is considered severe and the typical symptoms and treatment options for severe hyperopia.
What Causes Farsightedness?
Farsightedness is usually caused by an eye that is too short relative to its cornea and lens. This means that light isn’t focused correctly by the time it hits the retina at the back of the eye. Here are some key reasons why the eye may be too short:
– Genetics – Research suggests there are inherited factors involved in developing farsightedness. It often runs in families.
– Aging – The lens inside the eye progressively stiffens with age. This makes it harder for the lens to change shape and focus light properly.
– Premature birth – Babies born prematurely often have underdeveloped eyes that are too short. This causes hyperopia from an early age.
In some cases, hyperopia is caused by the cornea having too little curvature for the length of the eye. But most often the eyeball itself is just too short.
Mild vs. Moderate vs. Severe Farsightedness
Doctors classify farsightedness into three main severity categories:
– Mild hyperopia – This is up to +3.00 diopters of correction needed. People may not notice or be bothered by mild farsightedness.
– Moderate hyperopia – This is between +3.00 to +6.00 diopters of correction required. People start experiencing more noticeable vision symptoms at this level.
– Severe hyperopia – This is above +6.00 diopters of correction needed. Vision problems become significant at this high level of farsightedness.
The diopter unit measures the optical power required to correct vision. So higher diopters equals stronger prescription eyeglasses needed. Anything above +6.00 diopters is considered severe farsightedness with major impact on visual function.
Signs and Symptoms of Severe Farsightedness
Here are some common signs and symptoms that indicate severe levels of hyperopia:
– Blurry near vision – Struggling to see objects up close like books, computers, smartphones.
– Squinting and eye strain – Constant squinting to try and temporarily improve focus.
– Headaches – Eye strain from squinting can lead to headaches.
– Difficulty concentrating – Hard time reading or doing close detailed tasks.
– Fatigue – Feeling wiped out visually after short periods of near work.
– Double vision – Seeing overlapping ghost-like images particularly when looking side to side.
– Words moving around on page – Text appearing distorted or wobbly when reading.
– Avoidance of near tasks – Disliking activities like reading due to visual discomfort.
– Poor school performance – Falling behind in school work because of vision difficulties.
If a comprehensive eye exam determines over +6.00 diopters of hyperopia correction is needed for clear vision, then farsightedness has reached a severe level. The stronger the eyeglass prescription required, the more impact there is on visual function and comfort.
When Should Children Be Evaluated for Severe Farsightedness?
Since vision is still developing in young kids, doctors don’t usually prescribe full vision correction initially. But children should have a complete eye exam by age 3 to 5 to check for severe hyperopia. Signs a child should be evaluated include:
– Squinting, rubbing eyes a lot, headaches
– Sitting very close to TV or holding books close
– Poor hand-eye coordination or delayed fine motor skills
– Limited attention span for reading/near tasks
– Struggling in school, not meeting academic milestones
– Avoiding close activities like reading or coloring
– Tilting head to one side frequently
If severe farsightedness is detected early in childhood, treatment can help avoid impacts on visual development and school performance. But hyperopia can also develop later or get worse around the teenage years as the eye grows, so continued screening is important.
Can Farsightedness Progress with Age?
Yes, farsightedness often progresses gradually over one’s lifetime. Even if hyperopia is mild in childhood, it commonly increases into adulthood. Here’s why farsightedness tends to slowly get worse with aging:
– The eyeball elongates slightly over time, causing light rays to focus even further behind the retina.
– The lens stiffens and loses flexibility, hampering its ability to change shape and focus light properly.
– Pupils get smaller, reducing the amount of light entering the eye. This makes near focus more difficult.
– Loss of focusing strength – eyestrain sets in faster when trying to see nearby objects.
For these reasons, a farsighted prescription often needs to be increased every few years in adults. It’s important to have regular comprehensive eye exams to monitor for worsening hyperopia and update prescriptions as needed. Severe farsightedness is more likely to develop from milder cases later in life.
Can Hyperopia Be Corrected with Eyeglasses or Contacts?
Yes, the standard treatment for farsightedness is wearing corrective lenses like eyeglasses or contact lenses. These work by adding optical power to the eye to help bend light rays correctly onto the retina. Here’s how the different types of corrective lenses can help:
Eyeglasses – Prescription glasses for hyperopia have convex lenses that add plus power for sharper distance and near focus. Glasses offer the advantage of convenient on and off wear. Bifocals or progressive lenses provide a gradient of power tailored for viewing objects at different distances.
Contact lenses – Contacts designed for farsightedness also have plus optical power to improve focus. Popular options include multifocal contacts with separate zones for distance, intermediate, and near vision. Contact lens benefits include wider unobstructed field of view and little fogging compared to glasses.
Reading glasses – Simple magnifying reading glasses can help mildly farsighted people see up close without needing to wear vision correction full-time. Reading glasses don’t correct distance vision though.
The stronger the farsighted prescription needed, the thicker eyeglass lenses orContacts have to be. So severe hyperopia may require high index lenses for optimal vision and cosmetic appearance.
Can Surgery Correct Severe Farsightedness?
For extreme cases of farsightedness above around +8.00 to +10.00 diopters, surgery may be recommended to permanently reshape the cornea and improve focus. Several outpatient surgical options can reduce or eliminate the need for glasses or contacts in severe hyperopia:
Corneal ring segments – These small plastic or silicone rings are implanted in the outer cornea to flatten the surface, a procedure called INTACS. This corrects mild to moderate hyperopia.
Laser vision correction – Customized ablation of corneal tissue by lasers like LASIK and PRK can increase the curve of the central cornea to correct higher amounts of farsightedness and astigmatism.
Phakic IOLs – These permanent intraocular lens implants are surgically placed in front of the natural lens to provide extra optical power. They are used for extreme farsightedness not fully correctable by laser procedures.
Refractive lens exchange – The eye’s natural lens can be removed and replaced with a custom artificial IOL lens to gain better focus. This offers broader correction range than lasers.
Surgery can reduce or eliminate vision correction needs in severe farsightedness. But potential risks such as infection, flap complications, dry eyes, and loss of vision must be carefully weighed against benefits for each individual patient.
What is Monovision for Correcting Farsightedness?
Monovision is a technique often used to allow farsighted people to see clearly at a range of distances without glasses or contacts. It involves correcting one eye for distance vision, while the other eye is set for near vision.
Here’s how monovision works:
– The dominant eye is corrected for distance with just enough plus power to allow clear far focus.
– The non-dominant eye is given extra strength overcorrection, so it is set for optimal near focus at the expense of distance clarity.
– The brain blends the two eyes’ inputs, allowing good vision at far and near. But intermediate range is still somewhat blurry.
Monovision can be implemented with eyeglasses, multifocal contacts, or intraocular implants during cataract or refractive lens surgery. Using lenses, it can be reversed. But with IOLs or refractive surgery, monovision is permanent.
Some adaption is needed to get used to monovision’s reduced depth perception. And eyeglare issues can occur driving at night. But many embrace monovision for its freedom from constantly switching glasses.
Conclusion
Severe farsightedness is typically defined as hyperopia of +6.00 diopters or greater. At this high level, significant symptoms like blurred near vision, headaches, and eyestrain occur that can make work, school, and everyday activities challenging. While milder hyperopia may not require correction, severe farsightedness needs treatment with eyeglasses, contacts, or refractive surgery to properly focus light onto the retina and achieve clear and comfortable eyesight at all distances. Staying on top of regular comprehensive eye exams is key to monitoring progression of hyperopia over one’s lifetime and updating prescriptions as needed.
