Technically known as myopia (my-O-pe-ah) nearsightedness is a vision problem that affects over 25 per cent of adults worldwide and it is the most common vision problem in the United States. Nearsighted people experience difficulty seeing objects at a distance but can see objects at close range. Myopia occurs because the eyeball is too long as measured from front to back. Thus light focuses in front of the retina instead of directly on it causing blurred distant objects.
Nearsightedness can be an inherited condition usually first noticed in children or teenagers and it progresses during periods of growth. There is little change after the age of 20 when growth is completed and vision stabilizes. Other factors including intense close vision activities such as reading or computer use might cause or exacerbate the condition.
Nearsighted people have blurred vision or cannot focus on distant objects. Other symptoms include:
- Headaches or eye strain
- Needing to squint to see distant objects clearly
- Poor school performance in children as they cannot see the blackboard
A comprehensive examination by an eyecare practitioner will include a test for nearsightedness. If diagnosed with myopia the prescription level usually involves a fraction number. For example a person with 20/25 vision can see at 20 feet what a person with perfect vision sees at 25 feet. The most popular way to treat myopia is by eyeglasses or contact lenses to alter the way in which light images enter the eye. In mild cases corrective lenses might only be necessary for certain activities such as driving. Those more severely affected wear the eyewear all day.
Refractive surgery or laser procedures are also effective treatments for nearsightedness but they carry greater risks. These include side effects such as dry eyes sensitivity to glare and halos around lights especially at night. These procedures are not for persons under the age of 18 years.
Finally orthokeratology is a non-invasive procedure involving the use of a series of specially designed rigid contact lenses that progressively reshape the curvature of the cornea over time.