Refractive Errors

The most common refractive errors are:

• Myopia (nearsightedness)
• Hyperopia (farsightedness)
• Astigmatism
• Presbyopia

If you are experiencing the following symptoms, it is highly possible that you suffer from a refractive error:

• Headache
• Squinting
• Distorted or blurry vision
• Poor night vision
• Eye strain or fatigue
• Inability to focus on fine details
• Difficulty seeing near or distant objects clearly
• Burning or aching eyes

Refractive errors can be treated with corrective eyewear or surgically with LASIK laser vision correction surgery to reduce or even eliminate the need for glasses or contacts. The team at CVP Physicians Dayton offers a full range of vision correction options designed to suit each patient’s unique needs and lifestyle.

Myopia

Myopia, also known as nearsightedness or shortsightedness, is a condition of the eyes in which nearby objects are clear and distant objects appear blurred. It is one of the most common conditions affecting people of all ages.²

When a person is nearsighted, this means their eye is too long in relation to the other focusing elements, or the cornea is overly curved. As a result, the light rays connect at a point in front of the retina and begin to separate before they can be properly focused, which causes blurry vision.

Almost a third of people in the United States experience some degree of nearsightedness. There is a hereditary component to nearsightedness and individuals with a family history of the disorder are more likely to develop it. Though a small percentage of people with myopia develop a form of retinal degeneration, the majority of nearsighted people have otherwise healthy eyes.

Diagnosis and Treatment of Myopia

Myopia is diagnosed during a routine comprehensive eye exam. Patients are often prescribed with corrective lenses, eyeglasses or contact lenses. These shift the focus of light directly onto the retina so that a clearer image is perceived.

At CVP Physicians Dayton, we also offer options like LASIK, PRK, or Advanced Intraocular Lenses (IOLs) to reduce, if not completely eliminate, the need for corrective eyewear. When you come in for your appointment, one of our knowledgeable eye care professionals will help you find the most appropriate solution for your specific needs as well as your lifestyle.

Hyperopia

Also known as farsightedness, hyperopia is a condition of the eyes in which the focus on distant objects is better than the focus on objects closer to the eye, making nearby objects appear blurry.

In people with hyperopia, the cornea is insufficiently curved or the eye is shorter than normal. This causes light rays to be focused past the retina, not on it.

Diagnosis and Treatment of Hyperopia

Hyperopia may not be diagnosed during a standard visual acuity exam (reading an eye chart), because people’s eyes can compensate for mild cases of farsightedness. During a comprehensive eye examination, however, an ophthalmologist will have the tools required to accurately diagnose this refractive error.

People with hyperopia are often able to achieve clearer near vision with the help of prescription glasses or contacts. At CVP Physicians Dayton, we also offer surgical treatment of hyperopia through LASIK, PRK, or Advanced Intraocular Lenses (IOLs).

Astigmatism

Astigmatism is an eye condition that affects a high percentage of the population. It results from an imperfect curvature of the eye that causes refractive error. This means that,when light enters the eye, it is not focused evenly onto the retina. Instead, it is focused either in front of or behind the retina, often resulting in blurred vision.³

There are two types of astigmatism: corneal, in which the shape of the cornea is irregular, and lenticular, in which the lens is imperfectly shaped. Corneal astigmatism is more common. Either type of astigmatism can occur in combination with nearsightedness or farsightedness.

Although the precise causes of astigmatism are unknown, heredity seems to be a factor. Astigmatism may be present at birth or it may be the result of:

• Eye injury
• Eye disease
• Eye surgery, often for cataracts

Astigmatism is frequently so mild that it does not require correction. When it does, there are several treatment options available.

Diagnosis and Treatment of Astigmatism

Astigmatism is diagnosed during a routine comprehensive eye examination. Fortunately, there are several options available to treat astigmatism.

Nonsurgical Treatments for Astigmatism

Nonsurgical treatments for astigmatism include corrective lenses of several types: eyeglasses, hard contact lenses and soft contact lenses. The specialists at CVP Physicians Dayton can help counsel patients on the most appropriate lens for their unique needs.

Surgical Treatments for Astigmatism

Surgical treatments for astigmatism include:

• Limbal relaxing incision (LRI) surgery
• LASIK or PRK surgery

Astigmatic-correcting cataract surgery

Where contact lenses reshape the eye only when they are worn (ortho keratotomy), laser vision correction surgery such as LASIK corrects astigmatism by permanently reshaping the surface of the eye.

Patients with severe astigmatism may still need to wear eyeglasses or contact lenses after surgery.

Presbyopia

Presbyopia is a condition that eventually affects everyone. It is caused by the natural aging process, during which the eyes gradually lose the ability to focus at a close range. In young eyes, the lens is flexible enough to change shape, assisted by the circular muscle around it. When focusing on a distant object, the muscle relaxes; when focusing on a near object, the muscle constricts. As the lens of the eye hardens with aging, it becomes less flexible and unable to change shape for nearby images. As a result, close objects appear blurred.⁴

One of the first signs of presbyopia is the need to hold reading materials at a distance in order to obtain clear focus. Symptoms of presbyopia tend to worsen in dim lighting, when the eyes are tired, or when alcohol has been consumed.

Diagnosis and Treatment of Presbyopia

Presbyopia is diagnosed during a routine comprehensive eye exam. Although presbyopia cannot be cured, there are alternatives to help patients focus more clearly on nearby objects. Our team of specialists at CVP Physicians Dayton can help find the best solution for you.

Nonsurgical Correction of Presbyopia

Presbyopia can be easily addressed with corrective lenses. Corrective lenses are available over-the-counter for simple, more minor corrections: from 1.00 diopter to 3.00 diopter. Patients who require greater correction for near vision, or who also have farsightedness or astigmatism, will require prescription lenses—including those with multiple lens powers (bifocal, trifocals).
There are also contact lens options for individuals with presbyopia. Monovision contact lenses (which work for many, but not all patients) correct for distance vision in one eye and close vision in the other. Multifocal contact lenses have two different prescriptions in each lens—one for up-close reading and one for normal distance.

Surgical Correction of Presbyopia

There are several ways to treat presbyopia with surgery. These include:

• Monovision LASIK or PRK surgery
• Refractive Lens Exchange (RLE)
• Corneal inlays
• Presbyopic-correcting cataract surgery

Patients should be aware that any surgical procedure carries some risk and that most eye surgeries are not reversible.

Our team at CVP Physicians Dayton can help counsel on the best approach for you.