Myopia (short-sightedness): Lenses for myopia correction
Lenses used to correct short-sightedness are concave in shape. In other words, they are thinnest at the centre and thicker at the edge.
These lenses are called "minus power lenses" (or "minus lenses") because they reduce the focusing power of the eye. By doing so, minus lenses move the focus of light in a shortsighted eye from a point in front of the retina backward — so it falls directly onto the surface of the retina. This shift corrects the blurry distance vision caused by myopia (shortsightedness), restoring clear vision.
The power of lenses that correct shortsightedness is measured in units called dioptres (D). The lens powers on an eyeglass prescription for myopia always begin with a minus sign. The higher the power number of the lens, the more myopia it corrects.
For example, a -6.00 D lens corrects twice the amount of shortsightedness as a -3.00 D lens.
High-index lenses typically are recommended for correcting shortsightedness greater than -3.00 dioptres. These lenses are thinner and lighter than regular plastic lenses, making them more attractive and comfortable.
Also, anti-reflective coating is highly recommended for lenses that correct shortsightedness. AR coating eliminates distracting reflections in the lenses, making them appear thinner and more attractive. Eliminating reflections also improves vision and comfort.
Ortho-k contact lenses are another choice for the correction of shortsightedness. These are specially designed rigid gas permeable (GP) contact lenses that not only correct existing myopia — they may actually help control myopia progression in children.
Finally, people with moderate to severe myopia may benefit from implantable lenses. Known as phakic IOLs, these tiny lenses work like contact lenses but are implanted surgically within the eye, directly behind the pupil. No maintenance is required, and phakic IOLs offer permanent correction of shortsightedness, similar to LASIK eye surgery.
To determine the best vision correction options for your needs, schedule an eye exam with an eye doctor near you.