20/20 vision is a term used to express normal visual acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at that distance. If you have 20/100 vision, it means that you must be as close as 20 feet to see what a person with normal vision can see at 100 feet.
The American Optometric Association recommends that children should have their first eye examination at age 6 months, then at 3 years of age, and then again before he or she enters school. Vision development and eye health problems can be more easily corrected if treatment is begun early.
Reading or working under low lighting does not have any harmful physical effect.
No. Eyeglasses and contact lenses allow you to see clearly and comfortably. After their removal, you see less comfortably. This contrast is what makes some people believe their vision is worse after wearing corrective lenses. Corrective lenses do not cure the vision disorder; they only correct the symptoms.
Eye exercises cannot eliminate or reduce one’s need for corrective lenses. They can, however, correct certain eye misalignment problems like strabismus. What is a lazy eye? Lazy eye, or amblyopia, is the reduction of central vision in one eye that is unassociated to any eye health problem. It can result from a failure to use both eyes together. Lazy eye is often associated with crossed-eyes (strabismus) or a large difference in the refractive power (anisometropia) between the two eyes. If amblyopia is diagnosed before the age of six, it can often be corrected with eyeglasses, prisms, vision therapy, and eye patches over the “good eye” to force the "lazy eye" to learn to focus.
Ophthalmologists are physicians (medical doctors) who specialize in the detection and treatment of eye diseases. Ophthalmologists may prescribe eyeglasses and contact lenses, medication, or perform surgery, as necessary. Optometrists are independent primary health care providers who examine, diagnose, treat and manage diseases and disorders of the eye. They prescribe eyeglasses and contact lenses and medications. Optometrists, however, do not perform surgery. Opticians adjust and fit optical products such as eyeglasses.
Yes. Exposure to excessive amounts of UV radiation can result in a condition called photokeratitis or snow blindness. The effect typically occurs at high altitudes on reflective snow surfaces or, less common, with a solar eclipse. Artificial sources of UVB such as sun tanning beds, a welder's flash, and lightning can also cause photokeratitis. Symptoms of photokeratitis include: red eyes, a foreign body sensation, excessive tearing, and extremes light sensitivity. Fortunately, these symptoms are usually temporary and rarely cause permanent damage to the eyes. Prevention involves sunglasses with 100% UVB protection and full coverage of the eyes (side shields).