Myopia
Myopia makes distant objects appear blurred.
Nearsightedness occurs when the physical length of the eye is greater than the optical length. For this reason, it often develops in the rapidly growing school-aged child or teenager, and progresses during the growth years, requiring frequent changes in glasses or contact lenses. It usually stops progressing as a person finishes growing in his or her early twenties.
- Nearsightedness affects males and females equally.
- Those with a family history of nearsightedness are more likely to develop it.
- Most eyes with nearsightedness are entirely healthy, but a small number of people with myopia develop a form of retinal degeneration.
Symptoms
- Blurred vision or squinting when trying to see distant objects (children often cannot read the blackboard, but can easily read a book)
- Eyestrain
- Headaches (uncommon)
You can compensate for nearsightedness by wearing eyeglasses or contact lenses, which shift the focus point to the retina. The use of glasses or contact lenses does not affect the normal progression of myopia, they simply focus the light so the nearsighted person can see distant objects clearly.
There are also several surgical procedures, including LASIK, that can be used to decrease the amount myopia.
There is a somewhat controversial procedure called CRT (Corneal Refractive Therapy) which uses rigid contact lenses to temporarily decrease the amount of myopia.
Hyperopia
Farsightedness is often present from birth, but children have a very flexible natural crystalline lens, which may help to compensate or even hide the problem. If you have family members who are farsighted, you are also more likely to become farsighted. Farsightedness can be a risk factor for glaucoma and amblyopia.
Symptoms
The refraction during your comprehensive eye examination will help diagnose the existence of hyperopia. Cycloplegic eye drops may be needed to be used in children to get an accurate measurement of their farsightedness, due to their excellent focusing abilities.
Treatment
Farsightedness is generally corrected with glasses or contact lenses. However, surgical options such as LASIK can also be effective treatment options.
Symptoms
- Blurred vision of close objects
- Sometimes in children strabismus (crossed eyes) may be present
- Eye strain
- Headache while reading
The refraction during your comprehensive eye examination will help diagnose the existence of hyperopia. Cycloplegic eye drops may be needed to be used in children to get an accurate measurement of their farsightedness, due to their excellent focusing abilities.
Treatment
Farsightedness is generally corrected with glasses or contact lenses. However, surgical options such as LASIK can also be effective treatment options.
Astigmatism
Astigmatism is a refractive error to the eye that causes distortion to ones vision at both distance and near. The amount of disturbance to the vision is related to the amount and location of the distortion. This distortion is generally caused by the cornea not being round; however, it can also be caused by the crystalline lens in the eye being irregular.
Symptoms
Astigmatism is diagnosed during the refractive portion of your comprehensive eye examination.
Treatment
Once it is determined that there is no pathological cause, such as kerataconus, disease or corneal injury, corrective lenses would most likely be prescribed. Frequently, the correction for astigmatism is just another part of a nearsighted or farsighted correction. This is referred to as the cylinder portion of the eyeglass or contact lens prescription.
Astigmatism is a refractive error to the eye that causes distortion to ones vision at both distance and near. The amount of disturbance to the vision is related to the amount and location of the distortion. This distortion is generally caused by the cornea not being round; however, it can also be caused by the crystalline lens in the eye being irregular.
Symptoms
- Blurred vision at both distance and near.
- Headaches
- Glare
Diagnosis
Astigmatism is diagnosed during the refractive portion of your comprehensive eye examination.
Treatment
Once it is determined that there is no pathological cause, such as kerataconus, disease or corneal injury, corrective lenses would most likely be prescribed. Frequently, the correction for astigmatism is just another part of a nearsighted or farsighted correction. This is referred to as the cylinder portion of the eyeglass or contact lens prescription.