Myopia
Nearsightedness
Diagnosis And Treatment
Myopia Control
What Is Myopia ?
Myopia, commonly known as nearsightedness. It is a very common eye condition that causes refractive eye disorder. Myopia affects the way light enters the eye, causing distant objects to appear blurry. It is one of the most prevalent vision problems worldwide and can affect people of all ages, although it often begins during childhood or adolescence.
Myopia is a prevalent vision disorder characterized by blurred distance vision due to the improper focus of light in the eye. It can be effectively managed and corrected with glasses, contact lenses, orthokeratology, or refractive surgeries.
Regular eye examinations, early diagnosis, and appropriate treatments can help individuals with myopia maintain good eye health and clear vision. For those concerned about myopia development or progression, consulting an eye care professional is essential to receive personalized advice and care.
What Causes Myopia ?
Myopia, also known as nearsightedness, is a common refractive eye disorder that affects how light is focused inside the eye, leading to blurred vision when looking at distant objects. It is a prevalent condition worldwide, and its incidence has been increasing in recent decades, particularly in urban and developed areas.
Myopia occurs when the light entering the eye is focused in front of the retina instead of directly on it. Due to this optical imbalance, objects that are far away appear blurry to those with myopia. However, objects at close distances can still be seen relatively clearly.
This happens due to one or a combination of the following factors:
1. Elongated Eyeball
In most myopic individuals, the eyeball is longer from the front to the back than in non-myopic individuals. This increased axial length causes light to converge too early, resulting in a focal point in front of the retina, leading to blurred distance vision.
2. Increased Corneal Curvature
The cornea is the clear, transparent, and dome-shaped front surface of the eye that covers the iris, pupil, and anterior chamber. It is the outermost layer of the eye’s focusing system and plays a crucial role in allowing light to enter the eye and bend (refract) it so that it properly focuses on the retina at the back of the eye.
Sometimes, myopia can occur if the cornea (the clear, front surface of the eye) is overly curved, which causes light to be focused before it reaches the retina.
3. Increased Lens Power
The eye’s lens is a flexible, transparent, and biconvex structure located behind the iris (the colored part of the eye) and the pupil. It plays a vital role in the visual system by helping to focus light rays onto the retina, which is the light-sensitive tissue lining the back of the eye. The lens, along with the cornea, is responsible for the eye’s ability to form clear images of objects at varying distances.
The ability of the lens to change its shape and refractive power allows us to have clear vision at various distances. This is essential for daily activities such as reading, driving, and watching television. The natural lens inside the eye may have a higher than normal power, causing additional bending of light that leads to myopic eye condition.
Diagnosis of Myopia
Myopia can be mild, moderate, or severe, depending on the degree of refractive error. It often starts during childhood and may progress during the teenage years until the eye stabilizes in early adulthood. Myopia is typically diagnosed through an eye examination by your eye doctor ( ophthalmologist ), which includes visual acuity tests and refraction measurements to determine the prescription needed for corrective lenses.
Myopia can be diagnosed through a comprehensive eye examination performed by an ophthalmologist. The examination may include:
1. Visual Acuity Test
In most myopic individuals, the eyeball is longer from the front to the back than in non-myopic individuals. This increased axial length causes light to converge too early, resulting in a focal point in front of the retina, leading to blurred distance vision.
2. Refraction Test
A refraction test, also known as a vision test or eye examination, is a standard procedure performed by an optometrist or ophthalmologist to assess a person’s vision and determine any refractive errors in their eyes. Refraction is the bending of light as it passes through the cornea and lens to focus on the retina, where the image is formed.
This test is also known as eye number test helps determine the precise prescription needed for corrective lenses by measuring how light is bent as it enters the eye.
3. Retinal Examination
The retina is a thin, delicate, and light-sensitive layer of tissue located at the back of the eye. It plays a crucial role in the visual system by converting light into neural signals that are sent to the brain, allowing us to see and interpret the world around us.
The retina contains millions of specialized cells, including photoreceptors, which are responsible for capturing light and initiating the process of vision. The eye doctor will examine the back of the eye (retina) to ensure there are no other eye conditions affecting your vision.
Treatment of Myopia
The primary goal of treating myopia is to provide clear vision by correcting the refractive error. Common treatment options include:
- Glasses: Eyeglasses with concave lenses (minus power) are the most common and straightforward way to correct myopia. These lenses help to move the focal point back onto the retina, improving distance vision.
- Contact lenses: Similar to glasses, contact lenses with concave surfaces are used to correct myopia. They provide better peripheral vision and are a popular choice for those who prefer not to wear glasses.
- Orthokeratology (Ortho-K): This is a special type of rigid gas-permeable contact lens that is worn overnight. It temporarily reshapes the cornea, providing clear vision during the day without the need for glasses or lenses. However, the effect is temporary, and regular use is required to maintain the results.
- Multifocal contact lenses: These lenses are used to correct both distance and near vision simultaneously, suitable for individuals with both myopia and presbyopia (age-related difficulty in near vision).
- Refractive surgery: For those seeking a more permanent solution, refractive surgeries like LASIK (Laser-Assisted In Situ Keratomileusis) and PRK (Photorefractive Keratectomy) are available. These procedures reshape the cornea to correct the refractive error.