(949) 768-0331
Dr. Lori Floyd O.D.
Optometry
Vision Conditions
20/20 Vision
What does 20/20 vision mean?
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. With 20/20 vision, one can see clearly at 20 feet what should normally be seen at that distance. With 20/100 vision, it means that one must be as close as 20 feet to see what a person with normal vision can see at 100 feet. 20/20 vision does not necessarily mean the eyes are healthy.
Does 20/20 mean perfect vision?
No. 20/20 vision only indicates the sharpness or clarity of vision at a distance. There are other important vision skills, including peripheral awareness or side vision, eye coordination, depth perception, focusing and color vision that contribute to your overall vision ability.
No. 15/15 vision means normal sharpness of vision at 15 feet just as 20/20 indicates normal acuity at 20 feet. For consistency, optometrists in the United States use 20 feet as the standard to express sharpness of vision.
​
Other countries express visual acuity in their own ways. In England, for example, optometrists express visual acuity in meters (6/6 is considered normal.)
Why do some people have less than 20/20 vision?
Visual acuity is affected by many factors. Less than optimum clarity may result from vision conditions like nearsightedness, farsightedness or astigmatism, or from eye diseases.
Will clarity of vision vary with distance?
Some people can see well at a distance, but are unable to bring nearer objects into focus. This condition can be caused by Hyperopia (farsightedness) or presbyopia (loss of focusing ability). Others can see items that are close, but cannot see those far away. This condition may be caused by myopia (nearsightedness).
If my vision is less than 20/20, what can I do?
A comprehensive eye examination by a doctor of optometry can diagnose those causes, if any, that are affecting one’s ability to see well.
In most cases, an optometrist can prescribe glasses, contact lenses or a vision therapy program that will help improve vision. If the reduced vision is due to an eye disease, the use of ocular medication or other treatment may be used.
Astigmatism
What is astigmatism?
Astigmatism is a vision condition in which light entering the eye is unable to be brought to a single focus, resulting in vision being blurred at all distances. Astigmatism is not a disease, but rather, a vision condition that is quite common. It often occurs in conjunction with other refractive errors like nearsightedness or farsightedness. Most people have some degree of astigmatism. However, only individuals with moderate to highly astigmatic eyes usually need corrective lenses. You may have to adjust to wearing eyeglasses or contact lenses if you do not wear them now. Other than that, astigmatism probably will not significantly affect your lifestyle. People with significant amounts of astigmatism will usually have blurred or distorted vision. Those with mild astigmatism may experience headaches, eye strain, fatigue or blurred vision at only certain distances. Astigmatism may change slowly. Regular optometric care can, however, help to ensure that proper vision is maintained.
Causes of astigmatism
Typically, astigmatism is caused by the front of your eye (the cornea) being more oval than round, and not allowing light to focus properly on the back of your eye (retina). The causes of this irregular shape vary. In some cases, it may be hereditary or it may result from such factors as pressure of the eyelids on the cornea.
Symptoms
-
Blurred Vision
-
Distorted Vision
-
Headaches
-
Eye Strain
-
Fatigue
Diagnosis
A comprehensive eye examination by your doctor of optometry will include testing for astigmatism.
Treatment
-
Prescription Eyeglasses
-
Contact Lenses
​​
Surgical Treatments
-
Astigmatic Keratotomy (AK)
-
Photorefractive Keratectomy (PRK)
-
LASIK
Farsightedness (Hyperopia)
What is farsightedness?
Farsightedness, or hyperopia, as it is medically termed, is a vision condition in which distant objects are usually seen clearly, but close ones are difficult to bring into proper focus. Farsighted people are the majority. The condition only presents a problem if it creates blurred vision, causes headaches or results in reading difficulties. It is estimated that over half the people who wear eyeglasses are wearing them because of a focusing problem due to farsightedness or presbyopia, a natural decrease in focusing ability at near distance. If you are farsighted, you involuntarily exert extra effort to maintain clear distance vision and even greater effort to see clearly at close range. This extra effort can cause fatigue, tension, discomfort and headaches. If the crystalline lens of the eye cannot bring the object being viewed into focus, blurred vision occurs.
Causes of farsightedness
If the length of your eyeball is too short or the cornea has too little curvature, near objects cannot be brought into sharp and clearly focused images. This condition is hereditary,
Symptoms
-
Difficulty concentrating and maintaining a clear focus on near objects
-
Headaches after close work caused by eye strain
-
Blurred Vision
-
Fatigue
Diagnosis
Farsightedness can be effectively diagnosed in a comprehensive optometric examination. Common vision screenings, often done in schools, are generally ineffective in detecting farsighted people. This is because these individuals can identify the letters on an eye chart with little difficulty.
Treatment
-
Prescription Glasses
-
Contact Lenses
-
In mild cases, your eyes may be able to compensate adequately without the need for corrective lenses.
Nearsightedness (Myopia)
What is nearsightedness?
Nearsightedness, or myopia, as it is medically termed, is a vision condition in which near objects are generally seen clearly, but distant objects are blurred and do not come into proper focus. Nearsightedness is a very common vision condition that affects nearly 30 percent of the American population. It normally first occurs in school age children. Since the eye continues to grow during childhood, nearsightedness generally develops before the individual reaches age 20. Most individuals adapt well to wearing glasses or contact lenses. For those individuals who feel glasses affect their image or interfere with their activities, contact lenses or refractive surgery may provide options to better meet their lifestyle and vision needs. In some cases, more severely nearsighted individuals may find the condition limits their choice of occupations.
Causes of nearsightedness
When your eyeball is too long or the cornea has too much curvature, light entering the eye is not focused properly. Hereditary factors often control the growth and development of the eye. However, some evidence supports the theory that nearsightedness may also be caused by the stress of too much close vision work.
Symptoms
-
Blurry vision when looking at distant objects
-
Headaches caused by eyestrain
-
The need to squint or partially close the eyelids to see clearly
-
Difficulty seeing while driving a vehicle, especially at night (night myopia)
Diagnosis
Nearsighted children are usually easy to identify because they often squint or have trouble seeing the chalkboard, the movie screen, the television set or other distant objects. A comprehensive optometric examination will include testing for nearsightedness.
Treatment
-
Prescription Eyeglasses
-
Contact Lenses
​​
Surgical Treatments
-
Radial Keratotomy (AK)
-
Photorefractive Keratectomy (PRK)
-
LASIK
-
Orthokeratology
Presbyopia
What is presbyopia?
Presbyopia is a vision condition in which the crystalline lens of your eye loses its flexibility. This results in progressive difficulty in focusing on close objects. Presbyopia is a natural part of the aging process. The effects of presbyopia gradually diminish the ability of the eye’s crystalline lens to focus properly, resulting in progressive loss of focusing power. As a result, periodic changes in your prescription are necessary to keep pace with these changes and keep things comfortable and clear. It varies from person to person. Although presbyopia may seem to develop suddenly, the actual decline takes place over the course of many years. Most people notice the onset in their early forties. Your occupational and recreational needs, along with other vision conditions you may have, will determine what kind of correction(s) you may benefit from and how frequently you will need them.
Causes of presbyopia
Your eye stops growing in your early teens. The lens, however, continues to grow and produce more and more cells. This continued growth eventually causes the lens to harden and lose some of its elasticity and, therefore, its focusing ability.
Symptoms
-
Presbyopia is first noticed by most as blur at the normal reading distance, with a need to hold reading material farther away to see clearly
-
Fatigue (and sometimes headaches) when attempting to do close work.
Diagnosis
A comprehensive eye examination will include testing of your near vision, and determine the extent, if any, of your presbyopia. This will also rule out other conditions (some serious) that might mimic presbyopia.
Treatment
-
Reading Glasses
-
Bifocals
-
Trifocals
-
Progressive Addition Lenses
-
Contact Lenses
-
or a Combination of the above
-
Multifocal Intraocular Lenses