Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
It is common for pharmacies, supermarkets, airports, and even dollar stores today to carry nonprescription eyeglasses,
sunglasses, and magnifiers. We hope this review will assist consumers with valuable information about these eye products.
Nonprescription eyeglasses
Nonprescription eyeglasses are primarily for people who can no
longer read fine print. This condition, called presbyopia or "old vision," usually begins at about the age of 35 and progresses until about the age of 55. This inability to focus clearly at near distances is a universal human aging condition.
Although over-the-counter (OTC) glasses do
not appear to harm vision, if they are not appropriate for a person's
eyes, they can cause eyestrain after prolonged use.
Most vendors offer standard and bifocal lenses, and some vendor locations also offer transitional lenses that lighten up indoors and darken when outdoors. The reading glasses may be available in both full reading vision or in bifocals. Bifocals, invented by Benjamin Franklin, have a lower segment to see up close, with an upper segment consisting simply of clear glass for distance.
The quality and durability of OTC eyeglasses vary widely. Cheap models—costing as little as a few dollars—may have lenses that scratch easily and distort vision. Expensive models—costing $50 or more—may incorporate some or all of the desirable characteristics of high-quality prescription lenses. There is no permanent harm to the eyes from wearing poorly focused or distorted lenses. However, eye strain, computer vision problems, and poor quality vision from cheap or improperly fitted eyeglasses can reduce productivity and accuracy.
Manufacturers rate the power of nonprescription glasses from weakest (+1.0 diopters) to strongest (+3.5 diopters or more). When making a selection, the customer tries on eyeglasses and reads fine print while standing 12 to 14 inches from the print, or simply holding the printed material at a comfortable, customary reading distance. The customer keeps trying on glasses with different power ratings until the print comes into sharp focus. Suppose, for example, the print comes into focus when the customer is wearing eyeglasses with a power rating of +2.0. The customer then knows that a +2.0 rating is correct and can select from styles with that rating.
As we age, our eyes continue to lose the ability to focus up close. This phenomenon (presbyopia) is a result of many factors, including loss of elasticity of the natural human lens with time. Thus, a younger person first requiring reading glasses may require only +1 diopter lenses, which may progress with time to +2.50 diopter lenses.
A cataract is an eye disease that causes the eye's lens to become cloudy and opaque with decreased vision. Causes of cataracts include diabetes, hypothyroidism, certain genetic illnesses, hyperparathyroidism, atopic dermatitis, and certain medications. Symptoms and signs include a decrease in vision and a whitish color to the affected eye. Treatment depends upon the patient's specific visual needs and may involve cataract surgery.
Many common eye disorders resolve without treatment and some may be managed with over-the-counter (OTC) products. It's important to visit a physician or ophthalmologist is the problem involves the eyeball itself or the condition hasn't improved after 72 hours of use of an eye-care OTC product.
Eye strain is a symptom caused by looking at something for a long time. Symptoms and signs include redness, light sensitivity, headaches, and blurred vision. Symptoms may be treated by closing the eyes and taking a break from the visual task.
Astigmatism is a common eye condition that's easily corrected by eyeglasses, contact lenses, or surgery. Symptoms of astigmatism are headaches, fatigue, eyestrain and blurred vision.
Blindness is the state of being sightless. Causes of blindness include macular degeneration, stroke, cataract, glaucoma, infection and trauma. Symptoms and signs may include eye pain, eye discharge, or the cornea or pupil turning white. Treatment of blindness depends upon the cause of the blindness.
Age-related macular degeneration (AMD) is a disease that gradually destroys the central vision. In people over 60, AMD is a leading cause of vision loss. Wet AMD occurs when abnormal blood vessels behind the retina start to grow under the macula, leaking blood and fluid and causing rapid vision loss. In dry AMD, light-sensitive cells slowly break down in the macula, resulting in gradual vision loss. Pain is not associated with either form of AMD.
The term eye strain is frequently used by people to describe a group of
symptoms which are related to use of the eyes. Eye strain is a symptom, not an
eye disease. Eye strain occurs when your eyes get tired from intense use, such as
driving a car for extended periods, reading, or working at the computer. If you
have any eye discomfort caused by looking at something for a long time, you can
call it eye strain.
Although eye strain can be annoying, it usually is not serious and goes away
once you rest your eyes. In some cases, signs and symptoms of eye strain are a
sign of an underlying eye condition that needs treatment. Although you may not
be able to change the nature of your job or all the factors that can cause
eye strain, you can take steps to reduce eye strain.
What causes eye strain?
The medical term for eye strain is asthenopia. The symptoms of ocular
fatigue, tired eyes...