Fuzzy sight due to a refractive error is the most common of all vision problems. The fundamental reason for all refractive errors is light rays missing the retina because of eye shape.
You can see clearly if light rays are refracted (bent) to be focused on the retina. Cornea and lens are the parts of your eye doing this refraction. The cornea is a fixed shape and the lens changes shape, known as accommodation. Refracting light on the retina depends on the curvature of these two eye parts.
So, if your cornea is misshaped or your lens fails to change shape appropriately, then a refractive error results. And blurry vision is what you’ll experience.
The most prevalent refractive errors are hyperopia (farsighted), myopia (nearsighted), presbyopia and astigmatism. And sooner or later nearly everybody is affected by a refractive error.
Farsighted hyperopia means that objects at a distance are clear and the up close stuff is blurred. Farsightedness is caused by a cornea not being curved enough or your eye is too shorter. Therefore, light is refracted to behind the retina.
This refractive error is usually present at birth and being farsighted tends to run in families. Symptoms of hyperopia are:
- burning eyes
- close object blurriness
- computer related eyestrain
- close task caused headaches
Strabismus is a possible complication for the farsighted.
Nearsighted myopia is the type of refractive error that allows you to see close stuff perfectly, but far away things are a blur. Nearsightedness is caused by either your cornea being curved too much or your eye is excessively long. Thus, light is refracted in front of your retina.
This refractive error generally begins in childhood, worsens as you age and then stops. Myopia causes blurriness, headaches and eyestrain as well. And if you are severely nearsighted, then the risk for glaucoma, retinal tear and retinal detachment is increased.
Presbyopia is that “seeing up close” issue many aging folks experience because their lens accommodation ability is hampered by the loss of its elasticity. This refractive error typically comes into play around age 40. Although, those with myopia may not notice this vision deficit until later on. Whereas, certain health conditions, like diabetes and hypertension, can speed up the refractive error process.
Presbyopia cannot be prevented, but increasing the brightness of light, moving the item farther away and using a pair of reading glasses will lend a visual hand.
Astigmatism is an imperfection in your eye’s curvature. So instead of your eye being curved evenly and smooth, its shape is distorted with flat or steep spots. This refractive error blurs your vision no matter the distance. And astigmatism may exist in concert with other refractive errors.