Myopia is the most common form of refractive error today. It is otherwise known as short sightedness, which is the inability to see objects at a distance clearly. Common symptoms include squinting to see distance objects and or moving close to objects to focus. Myopia occurs due to the eyeball being longer than normal, causing the light rays to focus in front of the retina, resulting in a blurred image. The cause of this can either be due to one’s genetics or lifestyle. Correction for myopia includes spectacles, contact lenses and optical surgery.
Hyperopia is the opposite of myopia. It is known as farsightedness, which is the inability to see objects near us closely. Common symptom include holding books or our phones further away in order to see clearer. Hyperopia occurs due to the eyeball being shorter than normal, causing the light rays to focus behind the retina, resulting in a blurred image. Most hyperopic children have no problem focusing at near objects as their eyes are able to accommodate to focus near. Correction for hyperopia includes spectacles, contact lenses and optical surgery.
Presbyopia is another form of farsightedness. The symptoms are similar to hyperopia but occur in older people. As we age, the lens in our eyes hardens and loses its flexibility. The eye muscles also weaken. Thus, reducing our ability to accommodate and focus on near objects. Presbyopia usually occurs in the mid-40s and can gradually worsen up to 60 years of age. Correction for presbyopia includes progressive or bifocal spectacles, multifocal contact lenses or refractive surgery.
Astigmatism is another form of refractive error. It occurs due to our cornea or lens having an irregular shape, which causes light to defocus on our retina. It is usually present at birth and also commonly found in people with myopia or hyperopia. Symptoms include objects not being clear at all distances. Correction for astigmatism includes spectacles, contact lenses and refractive surgery.