Myopia or Nearsightedness is a medical vision problem where the patient is able to see the objects which are close by quite clearly; however, the objects present far away appear hazy or blurry. A person's ability to focus on faraway objects depends on the extent or the severity of nearsightedness. Patients having severe nearsightedness are only able to see those objects clearly which are present just a few inches away; whereas patients having nearsightedness, which is mild, can clearly visualize objects present many yards away.
The development of this condition can be rapid or gradual. Nearsightedness tends to worsen during childhood and teenage period. It is also hereditary.
A simple eye exam helps in confirming the diagnosis of nearsightedness. This condition can be corrected easily by wearing right contact lenses or eyeglasses. Surgery can also be done for nearsightedness.
Causes of Myopia or Nearsightedness
In patients having myopia also known as nearsightedness, the focus of the light rays, instead of being on the retina, is in front of retina resulting in blurry vision. Some of the common causes for this condition are:
Refractive Error is a condition where the cornea or lens does not curve evenly or smoothly. This results in the light rays not getting refracted in a proper manner resulting in a refractive error. Nearsightedness or myopia is a type of refractive error.
Other Refractive Errors Include
- Farsightedness or Hyperopia is also a refractive error and occurs when the curvature of the cornea is very less or if the eye is shorter than normal. This results in a condition which is opposite to that of nearsightedness. The light rays get focused outside the back of eye resulting in blurry vision. With some difficulty, one can focus on distant objects to be able to see them clearly. With more effort, one can focus on nearby objects so as to see them clearly. Blurry vision occurs as a result of ageing of the crystalline lens resulting in loss of its ability to focus and its flexibility. Patient is generally able to see distant objects quite clearly.
- Astigmatism is another refractive error which occurs when the curvature of the cornea is steep in one direction. If left uncorrected, it results in blurry vision which is often more blurry in one direction than another.
Risk Factors for Myopia or Nearsightedness
- Family history of nearsightedness.
- Occupations involving close work such as working on a computer or reading.
Complications of Myopia or Nearsightedness
- Patient's quality of life is greatly affected as he/she has difficulty in performing day to day tasks with limited vision.
- Patient suffers from headaches and eyestrain from squinting.
- Impaired vision jeopardizes the safety of the patient as well as others especially when operating heavy machinery or driving.
- Extreme nearsightedness increases the risk of developing glaucoma, which is a serious disease of the eye.
- Patient has a risk of developing retinal tear and detachment.
Signs and Symptoms of Myopia or Nearsightedness
- Blurry or hazy vision when visualizing faraway objects.
- Patient squints in an effort to see more clearly.
- Headaches caused by excessive eyestrain.
- Driving becomes difficult, especially driving at night.
- Symptoms in children are: relentless squinting, sitting very close to television, computer or in classroom, excessive blinking, holding books at close quarters during reading, oblivious to distant objects and frequently rubbing eyes.
Investigations for Myopia or Nearsightedness
A complete eye exam helps in diagnosing this condition.
Treatment for Myopia or Nearsightedness
The aim of treatment is to focus the light on retina using corrective lenses or refractive surgery.
Corrective Lenses help by neutralizing the increased corneal curve or the increase in eye length. There are various corrective lenses such as:
- Eyeglasses are available in many styles and they can be used easily. Eyeglasses help in correcting many vision problems such as astigmatism and myopia at one time. Other than this, eyeglasses are an inexpensive solution for correcting vision problems.
- Contact Lenses are available in much variety such as soft, hard, bifocal, rigid gas permeable, disposable, and extended wear. You can discuss with your eye doctor about which one is best suitable for you.
- Refractive Surgery: This treatment comprises of reshaping the curve of the cornea resulting in corrected vision. Refractive surgery options are:
- LASIK Surgery: LASIK stands for Laser-assisted in-situ keratomileusis and this procedure involves making a narrow, circular cut; like a flap, extending partially into the cornea. The surgeon removes the layers from the middle of the cornea so as to even out the dome shape.
- LASEK Surgery: LASEK stands for Laser-assisted subepithelial keratomileusis and in this procedure, instead of making a flap in the cornea, the flap is made in the epithelium of the cornea. A laser is used to reshape the outer layers of the cornea and to compress the curvature. The epithelial flap is then repositioned. A bandage contact lens can be worn after the procedure. This helps in promoting the healing process.
- Photorefractive Keratectomy: This resembles LASEK procedure; the difference being the epithelium is removed here, which grows naturally back according to the new shape of the cornea. A bandage contact lens should be worn after the procedure.
- Intraocular Lens Implant: These lenses (IOL) are implanted surgically anterior to the natural lens of the eye. Patients having moderate myopia or severe myopia are suitable for it. These days, intraocular lens implants are not used as a main line of treatment.
- Complications of Eye Surgeries Include: Infection, blurred distant vision, corneal scarring, loss of vision and aberrations in the vision.
Lifestyle Changes for Myopia or Nearsightedness
There is no method as such till date which can help in preventing this myopia; however, for good eye health you can do the following:
- Get regular eye checkups.
- Health conditions which are chronic in nature, such as hypertension and diabetes, should be monitored and controlled closely.
- If you experience symptoms such as abrupt loss of vision, blurred vision, light flashing, halos or black spots or rainbows surrounding the lights; they may indicate serious problems such as retinal detachment/tear, stroke or acute glaucoma; so you should seek immediate medical attention if you experience any of the above mentioned symptoms.
- Always shield your eyes from sun by wearing sunglasses having UVA and UVB protection.
- Always follow a healthy diet especially which is rich in vitamin A and beta carotene including such as, fish and leafy green vegetables.
- Quit smoking.
- Always use appropriate eye wear or glasses.
- Always use proper lighting when reading or working at close quarters such as in front of the computer.