If you have blurry vision, you’re not alone, so do about half of all U.S. adults according to a major survey conducted by researchers at the National Eye Institute.
The way your eyes bend, or refract light waves can cause problems with how you see leading to common refractive errors known as nearsightedness, farsightedness and astigmatism. Refractive errors are disorders, not diseases. Simply put, a refractive error means that the shape of your eye does not bend light correctly resulting in a blurred image. Light has to be refracted or bent by the cornea and the lens of the eye then focused on the retina in order for us to see.
Refractive errors are widespread, based on a survey of more than 12,000 adults conducted over a five year period. Results were reported in the in the August 2009 issue of Archives of Ophthalmology.
The survey found that:
- Of those who responded, 10% were farsighted, 33% were nearsighted and 36% had astigmatism.
- People older than 60 were more likely to be farsighted than nearsighted.
- Hispanics were less likely to have any kind of refractive error, 44 %, compared with Caucasians, 53%, and African-Americans 49%.
Researchers in the survey report said, “Refractive error is . . . the most common condition affecting the ocular health of the U.S. population, involving young adults, middle-aged persons and older adults of all ethnicities,”
Refractive error definitions are as follows:
Nearsightedness, or myopia, as it is medically termed, is a refractive error in which near objects are seen clearly, but distant objects do not come into proper focus. Nearsightedness occurs if your eye is too long or the cornea has too much curvature, so the light entering your eye comes to focus in front of the retina resulting in blurred vision.
Farsightedness, or hyperopia, is a refractive error in which distant objects are usually seen clearly, but close ones do not come into proper focus. Farsightedness occurs if your eye is too short or the cornea has too little curvature, so light entering your eye in theory focuses behind the retina. Obviously light can’t focus behind the eye so a blurred image is the result.
Many people mistake presbyopia for hyperopia. Presbyopia however, is a visual condition which becomes apparent in middle age. A loss of elasticity of the lens of the eye causes defective accommodation and the inability to focus sharply for near vision. Presbyopia begins around the age of 40 and many describe it as their arms being too short!
Astigmatism is a refractive error that causes blurred vision due to the irregular shape of the cornea. That is, the eye is shaped more like an egg than a golf ball resulting in two points of focus on the retina. Astigmatism can occur concurrently with nearsightedness and farsightedness.
Cockrell Eyecare Center offers a full range of refractive error correction options including glasses, contact lenses, and in-office LASIK surgery. If you or someone you know is struggling with blurry vision or have questions about vision correction, please contact our office to schedule an appointment. We can be reached in Stillwater at 405-372-1715. We also invite you to visit our website at www.cockrelleyecare.com and like us on Facebook at Cockrell Eyecare Center!