If you have emmetropia it means you have ideal distance vision and don’t need lenses to correct your vision. Show
 NearsightednessIf you are nearsighted it means that you can see well up close, but things at a distance appear blurry. Nearsightedness occurs when the cornea (the front of the eye) is too steep, or the eye is too long, and the light rays focus in front of the retina, rather than on the retina as they should. This condition can be corrected by glasses, contacts, lens implants or LASIK. FarsightednessIf you are farsighted it means you can see well at a distance, but things up close are blurry. Farsightedness occurs when the cornea (the front of the eye) is too flat or the eye is too short, and the light rays focus behind the retina, rather than on the retina as they should. This condition can be corrected by glasses, contacts, lens implants, or in some cases LASIK. AstigmatismIf you have astigmatism it means that your eye is not round, and instead is shaped like a football. This causes some of the light rays to focus on the retina and some to focus in front or behind the retina. This visual distortion can produce shadows, double images, or ghosting. Often people will have astigmatism combined with nearsightedness or farsightedness. This condition can be corrected by glasses, contacts, lens implants or in many cases LASIK. PresbyopiaSometime between the ages of 40-50 people start to have difficulty with reading vision. As the eye ages, the lens in the eye becomes harder, so the muscles have a more difficult time focusing the lens. This is called presbyopia. This condition can be corrected with reading glasses, contacts, lens implants and in some cases LASIK. Schedule an Appointment! Take the First StepFrom farsightedness to Astigmatism, Dr. Waters is able to help diagnose the problem and clearly explain the types of vision you are experiencing and how we can help. To get started towards better vision, the first step would be to schedule an appointment. Click here to schedule an appointment online. With typical vision, an image is sharply focused onto the retina. In nearsightedness (myopia), the point of focus is in front of the retina, making distant objects appear blurry. Nearsightedness (myopia) is a common vision condition in which near objects appear clear, but objects farther away look blurry. It occurs when the shape of the eye — or the shape of certain parts of the eye — causes light rays to bend (refract) inaccurately. Light rays that should be focused on nerve tissues at the back of the eye (retina) are focused in front of the retina. Nearsightedness usually develops during childhood and adolescence, and it usually becomes more stable between the ages of 20 and 40. Myopia tends to run in families. A basic eye exam can confirm nearsightedness. You can compensate for the blurry vision with eyeglasses, contact lenses or refractive surgery. Products & Services
SymptomsNearsightedness signs or symptoms may include:
Children may have difficulty seeing things on white boards or screen projections in the classroom. Younger children might not express difficulty seeing, but they may have the following behaviors that suggest difficulty seeing:
Adults with myopia may notice difficulty reading street signs or signs in a store. Some people may experience blurry vision in dim light, as with nighttime driving, even if they see clearly in daylight. This condition is called night myopia. When to see a doctorMake an appointment with an eye care specialist if your child exhibits any signs of vision problems or if a teacher reports possible problems. Make an appointment for yourself if you notice a change in your vision, have difficulty performing tasks such as driving, or find the quality of your vision detracts from your enjoyment of activities. Seek emergency medical care if you experience any of the following:
These are warnings signs of the retina becoming detached from the back of the eye. This condition is a medical emergency requiring prompt treatment. Significant nearsightedness is associated with an increased risk of retinal detachment. Regular eye examsBoth children and adults may not be aware of problems with vision or changes that happen gradually. The American Academy of Ophthalmology recommends regular vision screenings to ensure a timely diagnosis and treatment. Children and adolescentsYour child's pediatrician or other health care provider will conduct relatively simple exams to check the health of your child's eyes at birth, between 6 and 12 months of age, and between 12 and 36 months of age. If there are any problems, you may be referred to a medical doctor specializing in eye health and care (ophthalmologist). Vision screenings are tests to check for vision problems. A screening test may be performed by a pediatrician, ophthalmologist, optometrist or other trained provider. Vision screenings are often offered at schools or community centers. The recommended times for screening are as follows:
If a problem is identified in a screening test, then you'll need to schedule a complete eye exam with an optometrist or ophthalmologist. AdultsThe American Academy of Ophthalmology recommends that healthy adults with no known problems with vision or eye disease should get a complete eye exam on the following schedule:
If you have diabetes, a family history of eye disease, high blood pressure, or other risks of heart or vascular disease, you'll likely need more-regular eye exams. Also, you'll likely need more regular exams if you already have prescription glasses or contacts or if you've had surgery for vision correction. Your health care provider or eye care specialist will recommend how often to get an exam. Request an Appointment at Mayo Clinic CausesYour eye has two parts that focus images:
In order for you to see, light has to pass through the cornea and lens. They bend (refract) the light, so that the light is focused directly on the nerve tissues (retina) at the back of your eye. These tissues translate light into signals sent to the brain, which enables you to perceive images. Refractive errorsNearsightedness is a refractive error. This problem occurs when the shape or condition of the cornea — or the shape of the eye itself — results in an inaccurate focusing of the light passing into the eye. Nearsightedness usually results from the eye being too long or oval-shaped rather than round. It may also result from the curve of the cornea being too steep. These changes result in light rays coming to a point in front of the retina and crossing. The messages sent from the retina to the brain are perceived as blurry. Other refractive errors include:
Risk factorsCertain risk factors may increase the likelihood of developing nearsightedness, such as the following:
ComplicationsNearsightedness is associated with a variety of complications from mild to severe, such as:
By Mayo Clinic Staff Request an Appointment at Mayo Clinic Diagnosis & treatment Sept. 16, 2022 Share on: FacebookTwitter Show references
Related
Associated Procedures
Products & Services
Nearsightedness
AdvertisementMayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. What term describes a defect in which light rays focus in front of the retina?Myopia occurs when the images that enter the eye focus in front of the retina. In many cases, the eyeball is too long and so the focal point of light falls in front of the retina. The cause of myopia is not precisely known, but it may be caused by a combination of environment and genes.
What is it called when light rays come into focus in front of retina due to a lengthened eyeball or over curved lens causing fuzzy distance vision?Nearsightedness (myopia).
This occurs when the cornea is curved too much or the eye is longer than usual. Instead of being focused precisely on the retina, light is focused in front of the retina, making distant objects seem blurry.
What is the medical term for the inability to focus light rays?Refractive errors are a type of vision problem that makes it hard to see clearly. They happen when the shape of your eye keeps light from focusing correctly on your retina (a light-sensitive layer of tissue in the back of your eye). Refractive errors are the most common type of vision problem.
What is myopia and astigmatism?Astigmatism, hyperopia and myopia are the most common (20%) eye problems seen in children. Astigmatism is a condition where the curve of the cornea (the clear round part in the front of the eye) is abnormal. Hyperopia is when objects up close are seen out of focus. Myopia is when distant objects are seen out of focus.
|
Select the medical term that means: a defect in which light rays focus in front of the retina
zusammenhängende Posts
Urheberrechte © © 2024 nguoilontuoi Inc.
