Despite being around for several hundred years, eyeglasses continue to grow in popularity due to advances in materials and greater choices in style. If you are interested in learning more about eyeglasses, the team at our Wilmington eye care center can help. Our outstanding vision care professionals can provide a comprehensive eye exam and help you determine the best glasses for your needs and lifestyle. With a reputation for being both friendly and knowledgeable, we are here to answer your questions and provide you with outstanding service in eye care. To schedule an appointment, contact us today.
How Glasses Provide Proper Focus
Glasses correct vision problems that result from the eye’s inability to focus light properly on the retina. Reasons for this aberration include having an improperly shaped cornea, or the inability of the lens to change its curvature to correctly match the image. The most common vision problems are:
- Myopia (nearsightedness): The image comes into focus before it reaches the retina, causing distant objects to appear blurry.
- Hyperopia (farsightedness): The image does not come into focus before it gets to the retina, so close objects appear blurry.
- Astigmatism: Distortion of the cornea causes images across all distances to appear blurry.
By placing a lens in front of the eye, glasses change the focal point according to the specific vision problem. The lens bends light in a certain direction to compensate for the aberration. Patients with myopia need a lens that pushes the focus of the eye farther back. These lenses are called minus lenses. Patients with hyperopia need a lens that pushes the focal point forward. These lenses are called plus lenses. Patients with astigmatism need customized lenses that bend light along an axis depending on the individual’s corneal distortion.
Exams for Eyeglass Prescriptions
The type of lens needed to correct your vision, as well as the lens strength, is determined during an eye exam. The exam will not only test for visual impairment, but also for other underlying health issues. Several tests and screenings will be used to examine your eyes. The test used for eyeglass prescriptions is called refraction. The doctor uses an instrument called a phoropter to show you a series of lens choices while asking you which of two lenses in each choice looks clearer. Alternatively, an autorefractor or aberrometer may be used to determine prescription. These devices perform an automated test that takes less time than a phoropter, and the measurements are very accurate. Aberrometers are most often used for LASIK vision correction, but also may be used for routine eye exams.
Determining Lens Strength
Lens strength is determined by the material the lens is made from, as well as how much the light needs to be bent. This power is measured in diopters (D). The higher the diopter number, the stronger the power of the lens. A plus or minus sign preceding the diopter power on your prescription shows the type of lens.
Advantages of Eyeglasses
Modern advancements have made glasses thinner, lighter, and more attractive than ever before. If you do not mind wearing them, glasses offer some solid advantages. Glasses are accurate and predictable, and they are less expensive than contact lenses or refractive surgery. They are easy to take care of, and they are unlikely to cause side effects.
We are focused on your vision needs and committed to your satisfaction. To learn more about glasses or schedule an appointment for an eye exam, contact our friendly, professional staff today.