Refractive Error Definition, Reason, Symptoms, Treatment & Prevention
Understanding
Refractive error, or in the medical language it is called ametropia, is a condition when the image formed on the retina of the eye is neither sharp nor firm. This results in blurred vision.
Refractive errors can be divided into four, such as:
• Myopia (nearsightedness)
• Hypermetropia (farsightedness)
• Presbyopia (old eyes)
• Astigmatism (cylindrical eyes)
Myopia
Myopia is called nearsightedness because of the reduced ability to see far, but still good near vision. Symptoms of myopia are vision that looks blurry when looking at a distance and is only clear at relatively close distances. Of course, this situation causes disruption in work, because sometimes it can be accompanied by headaches. Myopia can be corrected by using the lightest minus or negative lens of the appropriate size, to reduce the power of refraction in the eye.
Hypermetropia
Hypermetropia is a condition in which the image of the eye is focused behind the retina. Patients with hypermetropia will find it difficult to see at close range.
To treat hypermetropia, you should be given the largest positive lens glasses that still provide maximum visual acuity.
Presbyopia:
Presbyopia is a condition in which the ability to see up close gradually decreases. This is related to the age factor.
Presbyopia symptoms usually appear after the age of 40 years. Some of the symptoms, namely the eyes feel tired after reading, read by moving away the paper being read, often needing a brighter light to read, and difficulty reading at night.
Astigmatism
Astigmatism is a visual disorder caused by abnormalities in the curvature of the lens. Some of the symptoms of this condition are tired eyes, dizziness, blurred vision when looking far away while seeing up close is better, unfocused views, and difficulty seeing the full picture.
To treat astigmatism, doctors will advise people with astigmatism to use cylindrical lenses.
Symptoms
Usually, symptoms of refractive errors begin with complaints of headaches, especially in the nape or forehead area. In addition, sufferers also complain of watery eyes, drowsy quickly, stinging eyes, sore eyes, and blurred vision.
Blurred vision depends on the type of disorder experienced. In people with myopia, vision is blurred when looking at a distance. Meanwhile, in patients with hypermetropia, vision is blurred when looking closely.
If refractive errors are not treated, it can cause a loss of visual acuity that is getting worse and reduces productivity.
Reason
Refractive errors can be caused by defects/disorders in the curvature of the eye organs, namely the cornea and lens. This causes changes in the refractive index of the eye and abnormalities in the length of the eyeball axis.
Not only that, genetic predisposition also has a big role. If you have parents or siblings who suffer from refractive errors, you will most likely experience it.
Diagnosis
To diagnose refractive errors, the doctor will perform a visual acuity examination. In addition, there is also a refraction examination which consists of subjective refraction and objective refraction.
It is best to start eye examinations when you are a child, that is, before the age of 5 years. In the age range of 20-50 years, ideally eye examinations are carried out every 1-2 years. After the age of 50, it is recommended to have an eye examination every year.
Treatment
When refractive errors are so disturbing, it is advisable to immediately visit an ophthalmologist. However, it should be noted that the use of glasses cannot cure refractive errors. Likewise by increasing the intake of foods that contain vitamins A, B, and C.
Basically, the need to correct refractive errors depends on the patient’s symptoms. Patients with mild refractive error may not require correction. However, there are also those who need glasses or contact lenses.
Apart from that, you can also do LASIK or laser-assisted in situ keratomileusis surgery. The success rate can reach 90%. However, just like any other surgical procedure, LASIK surgery can also cause side effects. For example overcorrection, under correction, glare, infection of the cornea, even loss of vision (although this is rare).
Other surgical therapies that can be performed include implanting an artificial lens in front of the eyepiece, lens removal, radical keratotomy, and automated lamellar keratoplasty. Before doing therapy, consult first with an ophthalmologist.