This is a common type of refractive error where close objects appear clear but distant objects appear blurred. In Myopia, the eyeball is too long to refract light properly and focus it on the retina at the back of the eye to see images clearly.
What causes Myopia?
The underlying cause for this eye condition is thought to be a combination of two main factors; environmental and genetic factors. The common risk factors include family history of nearsightedness, doing a lot of work that involves focusing closely on objects, and spending much of the time indoors.
Most common signs and symptoms of myopia
- Distant objects such as road signs and a chalkboard appear blurry
- Persistent squinting to see clearly
- Blinking excessively
- Headaches as a result of eyestrain
- Rubbing eyes frequently
- Holding reading materials very close to your eyes
- Sitting closer to the television or movie screen
In most cases, eye doctors usually recommend eyeglasses for correction of the condition. Eyeglasses help compensate for the curvature of the cornea or the elongation of the eye simply by shifting the focus of light rays when entering the eye. The amount of myopia will determine how long you’ll need to wear the glasses. Patients who are very nearsighted may need to wear the glasses all the time. Others may be asked to wear them for certain activities, such as reading, driving a car, and watching a movie.
A single-vision lens is generally prescribed to provide patients with clear vision at short and far distances. But, patients who have crossed the age of 40, or adults and children whose condition is a result of the stress of near-vision work will probably need bifocal lenses (multifocal lens). These lenses provide different strengths to allow patients see distant and up close objects clearly.
2. Contact lenses
They help correct vision in a more similar manner as eye glasses, but offer a clearer vision and a wider field of view. Nevertheless, they require proper care because they are usually worn directly on the eyes.
3. Refractive surgery
This is a permanent correction for severe nearsightedness. It changes the shape of the cornea to eliminate the dependence on contact lenses or glasses. The common refractive surgery procedures include:
· Photorefractive keratectomy (PRK)
This type of surgery typically involves removing a thin layer of corneal tissue. It helps change the corneal curvature and allows light to focus more accurately on the retina. However, there is a limit to the amount of tissue that can safely be removed.
· Laser-assisted in situ keratomileusis (LASIK)
This is the most common procedure used to correct Myopia. The surgeon uses a laser and removes tissue from the inner layers of the cornea. This is usually done by cutting a section of the outer corneal surface and then folding it back so as to expose the inner cornea. A precise amount of tissue is removed to reshape the cornea. After that, the doctor places the flap of outer tissue back. Just like PRK surgery, the amount of corneal tissue that can be safely removed to correct nearsightedness using LASIK procedure is also limited.