We see a common vision problem in human beings called a Refractive Error. The error occurs when your eye can’t focus properly on images that appear on the retina. And this problem results in the blurriness of the vision. These errors can badly affect your regular lifestyle activities and the mobilities if they are not corrected. The problem might also become severe.
Whenever the size of the eyeball changes making it short or long or the shape of the cornea of the lenses within the eye changes, this refractive error can occur. It needs to be taken care of well. Otherwise, it can become very problematic.
Types of Refractive Error:
Also called near-sightedness, Myopia is a common vision error. It enables you to see objects that are near to you but distant objects appear blurry. The problem occurs when the light rays are focused only on the retina’s front instead of focusing on the retina. This can also be because of the long eyeball or too much focusing power of the eye.
You can develop myopia at any age. You can also correct it with glasses or contact lenses which can help in improving the quality of your vision. Myopia can improve in different amounts in childhood and is settled by the late teens to early twenties. Headache because of eyestrain and excessive blinking of eyes are the symptoms of Myopia.
Usually referred to as long-sightedness or farsightedness, Hypermetropia is a common eye problem. In this, nearby objects appear blurry, but your vision is clear when you look at things farther away.
This condition occurs when the light rays focus behind the retina instead of on the retina. It can be caused by small or short eyeballs or too little focusing power of the eye. It causes both near and far objects to be blurry.
Low to moderate amounts of hypermetropia is common in children. It can be easily treated by only the child’s own focusing mechanism. Hence, wearing glasses is not necessary. The problem reduces in children as the eyeball lengthens with the growth of the child. Although high hypermetropia in children might need specs correction, especially when it is related to an eye misalignment or lazy eye.
Moderate to high levels of hypermetropia in adults need spectacles correction. Eye strain, eye discomfort, or blurry near vision are some symptoms of hypermetropia.
Presbyopia is referred to as the loss of the eye’s ability to focus on near objects. It is an age-related vision error in which the ability of the eye to focus up close becomes quite difficult. This is mainly due to the hardening of crystalline lenses in the eye and the weakening of the focusing muscle.
Presbyopia causes difficulty in reading and other such activities. It affects individuals nearing age 40. Optical solutions such as glasses, contact lenses, etc can be helpful in correcting presbyopia. Cataract lenses with specially designed intraocular lens implants can correct presbyopia.
Astigmatism occurs usually when the cornea is more curved in a single direction rather than in others. It results in the light rays which are focused at some points behind or in front of the retina. It leads to a deformed image or blurry image.
The difference in curves that causes astigmatism can be easily understood whenever a normal eye is seen as a perfectly shaped round basketball but an astigmatic eye is usually irregularly shaped just like a rugby ball. Far or near vision can both be affected. It is often accompanied by myopia or hypermetropia.
So, it can be said that these refractive errors occur only when the eye is not able to focus on light properly on the retina. These are common errors and can be corrected with proper care.