All About Vision
The human eye works by refracting or focusing light through the cornea and lens so that the light rays are bent onto the retina. The retina's photoreceptors transmit visual data to the brain via the optic nerve for interpretation. If light rays are not focused properly on the retina, it's known as a refractive error. This can occur for various reasons, including an irregularly shaped cornea or an eye that is too long or short.
Refractive Errors and Vision Impairment
The most common refractive errors include:
- Myopia (nearsightedness) – Myopic people can see near objects clearly, but have difficulty seeing things at a distance.
- Hyperopia (farsightedness) – While it can be difficult to focus on objects in close range, farsighted people typically have good distance vision. Hyperopia is sometimes confused with presbyopia, due to similar symptoms, but the causes for these two conditions are completely different.
- Astigmatism – Irregularly shaped corneas or lenses impact vision at all distances. Those with astigmatism may experience blurry and distorted vision, eye strain and headaches if their astigmatism is not corrected.
Vision Correction
Most refractive errors can be corrected with contact lenses, eyeglasses or refractive surgery.
People elect to wear contacts for a variety of reasons, ranging from increased convenience to appearance. Whatever the reason, today's contact lenses are available in a variety of materials and varying replacement schedules. Due to advancements in the industry, people who previously could not wear contacts due to conditions like astigmatism and keratoconus can now be successful lens wearers. They may require custom contacts, which are available in both rigid gas permeable and soft lens materials.
Today's eyeglass frames allow people to express their own personality while improving their vision. Lenses are available in a variety of materials, coatings and designs. Modern lenses can be made out of shatter resistant materials, darken when exposed to sunlight and seamlessly transition between lens powers to enable wearers to focus near, far and in-between.
The newest method of refractive correction is refractive surgery. Although procedures like LASIK and PRK are talked about virtually everywhere, it is important to understand that even if a patient is a candidate for the procedure, the procedure itself may not be the best fit for their needs. Thorough research should be conducted before electing to have refractive surgery, including what to look for when deciding on a surgeon, what the potential risks are for the procedure and the associated surgery costs.
All About Vision contains several articles on refractive surgeries and a consumer-driven directory of skilled LASIK surgeons throughout the United States, Canada, Mexico and abroad. Potential patients can use the directory to locate an experienced specialist in their area and learn more about him or her prior to scheduling a consultation. The directory makes it easy to locate a surgeon for LASIK Los Angeles or another U.S. city.
Conditions
Eye conditions and diseases range from minor vision health concerns to severe illnesses that can result in blindness. Information on the causes, symptoms and treatment options for eye conditions like a stye or chalazion, itchy eyes, floaters and pink eye may not require a visit to the eye doctor, but it should be considered.
More serious eye health problems, such as a cataract, a detached retina, macular degeneration and glaucoma, require treatment from eye doctors.
Macular degeneration affects millions of Americans. Macular degeneration breaks down the macula (the light-sensitive part of the retina) resulting in debilitating loss of vision. Read about macular degeneration.
Glaucoma is the second-leading cause of blindness in the U.S. Elsewhere around the globe, glaucoma ranks as a leading cause of blindness just about everywhere. When intraocular pressure (IOP) levels are too high, peripheral vision will deteriorate until tunnel vision develops. Learn more about glaucoma.
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