What is myopia?
Myopia, also known as nearsightedness, is a common refractive error of the eye that affects a person’s ability to see distant objects clearly. People with myopia can see objects that are close to them clearly, but distant objects appear blurry. Myopia affects almost 42% of Americans.
Myopia occurs when the eyeball grows too long from front to back or the cornea is too curved. Instead of focusing images on the retina – the light sensitive tissue in the back of the eye that sends visual signals to the brain, images are focused in front of the retina. This causes distant objects to appear blurry, while close-up objects remain clear. Myopia can be caused by a combination of both factors.
What causes myopia?
There are several factors that can contribute to the development of myopia, including:
- Genetics: Myopia tends to run in families.
- Environmental factors: The implication that screen time on digital devices causes myopia is not supported by the science. However, studies suggest that spending too much time indoors, particularly on activities such as reading, and doing near work, that requires near focus, can make it difficult for the eyes to focus on the distance, and can increase the risk of developing myopia, especially in children but also in adults. Lack of outdoor activities and exposure to natural light can also be contributing factors.
- Age: Myopia develops during childhood and can progress throughout adolescence and into early adulthood. In most cases, the condition stabilizes once a person reaches their mid-20s.
- Eye conditions: Other conditions, such as cataracts, can also cause myopia.
- Medications: Certain medications such as corticosteroids can cause acute myopia, but rapid withdrawal of the drug leads to full recovery.
What are the symptoms of myopia?
Symptoms of myopia may include:
- Difficulty seeing distant objects clearly
- Squinting to see distant objects
- Eye strain or fatigue
- Blurry vision when looking at distant objects
How is myopia diagnosed?
Myopia is typically diagnosed during a comprehensive eye exam. The exam usually involves:
- Visual acuity test: The use of an eye chart to measure the sharpness of your vision at different distances. This test helps determine whether you have difficulty seeing distant objects clearly.
- Refraction test: This test determines the amount of nearsightedness you have by measuring how well your eye focuses light. The eye doctor may use a phoropter or an automated instrument to measure your refractive error and determine the correct prescription for corrective lenses, such as glasses or contact lenses.
- Examination of the eye’s structure: The eye doctor may use various instruments, such as a slit lamp, to examine the front and back of the eye’s structure. This helps detect any abnormalities that may be contributing to your myopia.
- Pupil dilation: The eye doctor may use eye drops to dilate your pupils, allowing them to see the inside of your eye more clearly. This helps detect any underlying eye conditions or complications associated with myopia, such as retinal detachment or macular degeneration.
How is myopia treated?
Treatment options depend on the severity of the condition and the individual’s lifestyle and preferences. The most common methods of treating myopia include:
- Corrective lenses: Glasses or contact lenses are the most common and non-invasive way to correct myopia. The lenses are designed to counteract the eye’s elongated shape or cornea curvature, allowing light to focus correctly on the retina. Prescription glasses or contact lenses need to be regularly updated to ensure optimal vision correction.
- Orthokeratology (Ortho-K): Ortho-K is a non-surgical procedure that uses specialized contact lenses worn overnight to temporarily reshape the cornea, correcting myopia during waking hours. This treatment can be particularly beneficial for individuals who do not want to wear corrective lenses during the day.
- Refractive surgery: Procedures such as LASIK (laser-assisted in situ keratomileusis) and PRK (photorefractive keratectomy) are surgical options for treating myopia. These procedures reshape the cornea, allowing light to focus correctly on the retina. Refractive surgery can be effective for people with moderate to severe myopia, and it offers the convenience of not needing corrective lenses.
If you experience symptoms of myopia, such as blurry vision or difficulty seeing distant objects, or have a family history of myopia, schedule a comprehensive eye exam with one of our ophthalmologists at Coastal Skin and Eye Institute with offices in Carmel Mountain and Encinitas, California. Early detection and management of myopia can help prevent complications and preserve your vision.