What are refractive errors in children?
Refractive also known as Optical errors like Myopia, Hyperopia and Astigmatism can cause unclear vision due to an insufficiency to focus images on the retina. If not corrected, the effects can be particularly dangerous for children, since vision is evolved in the first years of life.
Refractive errors are just one probable cause of unclear vision, so it is necessary for your child to have a test right away if they are undergoing any symptoms.
The most common refractive errors in children are:
Myopia (also called nearsightedness)
Hyperopia(also called farsightedness)
Astigmatism (distorted vision)
Any cause of bad vision in one or both eyes during young age, as is the case with refractive errors, can take to the condition known as "Lazy Eye".When the kid has hyperopia, astigmatism or myopia, the image that reaches the brain is not clear.
Myopia: A myopic eye is longer than usual or has a cornea that is too steep, so that the light rays focuses ahead of the retina. Near objects look clear, but the faraway objects appear unclear.
Hyperopia: A hyperopic eye is shorter than usual. Light from near objects cannot focus clearly on the retina. The letters on a page will seem unclear, or it will be hard to see well enough to do close-up tasks, like threading a needle.
Astigmatism: Astigmatism distorts or hazy vision for both near and far objects. It's almost like looking into a fun house mirror in which you look too tall, too wide or too thin. When you have astigmatism, the cornea (the clear front window of the eye) bends more in one direction than in the other like a football.
A usual cornea is round and smooth, like a basketball. It is likely to have astigmatism in combination with myopia or hyperopia.
What causes Refractive errors in children?
The dioptric power of the eye is determined by two important factors:
The most common refractive errors in children are :
The cornea and crystalline lens:They offer the eye with its convergence capability, since it is through the cornea and lens that light passes and joins to focus the image on the retina.
The axial length :The distance between the anterior and posterior poles of the eyeball, which governs the necessity for greater or lesser convergence of light, depending on whether the eyeball is longer (myopic) or shorter (hyperopic)
Myopia can rise as the infant grows. If the axial length of the eye rises, so does the degree of myopia. In contrast, hyperopia does not rise as the infant grows, but can reduce if the eyeball lengthens.