Myopia, or nearsightedness, is due to light focusing in front of the retina. This premature focal point is typically caused by a longer-than-average eyeball or a steep cornea. Symptoms of nearsightedness include:
blurred vision at distance
Spectacles and contact lenses help to diverge light so that it focuses sharply on the retina.
Hyperopia, or farsightedness, is due to light focusing behind the retina and is due to either a shorter-than-average eyeball or flat cornea. Symptoms of farsightedness include:
blurred vision at near
headaches associated with reading or near work
This can be corrected with eyeglasses and contact lenses.
In astigmatism, light rays focus at different points on the retina making vision at all distances blurred. Astigmatism typically means the cornea is shaped like a football rather than a basketball, having a long curve and a shorter, steeper curve. Symptoms of astigmatism include:
pain around the eyes
As with near- and farsightedness, eyeglasses, and contact lenses can typically correct blur associated with astigmatism.
Presbyopia is the process by which the ability to focus is reduced. This typically begins during the fourth decade and progresses into our 50′s. Eyeglasses and contact lenses can help to restore loss of focus.
Amblyopia is a disorder of the visual system characterized by a reduced vision in an eye that is otherwise physically normal. Amblyopia is the most common visual impairment in childhood, affecting approximately 3 out of every 100 children, and is due to differences in refractive errors between the eyes or strabismus (eye turn). In amblyopia, the brain receives different signals from each eye and begins to ignore the weaker eye. As this continues, the visual nerve fibers from the weaker eye do not develop as those fibers from the fellow eye. Unless treated successfully in early childhood, permanent reductions in vision and functional blindness can occur. At this point, further visual improvement can not be achieved with glasses, contact lenses, or surgery.
Amblyopia is treated by forcing the brain to acknowledge the weaker eye. This is typically accomplished by wearing a patch over the better eye for a period of time over weeks or months. The treatment goal is to reduce the visual signal from the better eye while allowing the fibers from the weaker eye to better develop. Length of treatment depends on the severity of amblyopia, age of the child, and achievable visual outcome. Amblyopia may also be treated using the medication, which blurs the visual signal from the better eye.
Signs to look for include:
Reduced vision in one eye
Squinting or closing one eye during reading or watching Television
An eye that turns in or out
Tilting or turning the head while viewing
Although recent research has suggested that amblyopia is treatable after childhood, detecting it early (before age 9) increases visual outcome. Therefore, Williamsburg Eye Care recommends having your child’s eyes examined early and frequently throughout adolescence.