Clearing the Blurry Vision: Causes, Treatment and Prevention of Myopia
- drgunjandeshpande
- Feb 28, 2023
- 10 min read
Updated: Nov 13, 2024
Myopia is becoming increasingly common worldwide, affecting an estimated 30% of the global population. It is a growing concern in India, with an estimated 49.2 million people affected by the condition.
According to a study published in the Indian Journal of Ophthalmology, the prevalence of myopia in India has increased significantly over the past few decades. The study found that while the prevalence of myopia was around 2-3% in the 1960s, it has now risen to around 30% in urban areas and 10-15% in rural areas.
Myopia, also known as nearsightedness, is a refractive error that affects the way the eye focuses light. People with myopia can see nearby objects clearly, but distant objects appear blurry.
This rise in myopia is believed to be linked to a range of factors, including changing lifestyles, increased use of electronic devices, and decreased time spent outdoors. In a country where children often spend long hours studying, the high prevalence of myopia is particularly worrying. According to the All India Ophthalmological Society, around 10-20% of Indian children between the ages of 5 and 15 have myopia, and this figure is expected to rise in the coming years.
Senior ophthalmologist, Dr. Gullapalli N. Rao has spoken about the need to raise awareness about myopia and its impact on eye health. He has said, "Myopia is a leading cause of irreversible blindness, and we need to take urgent action to prevent its spread."
This blog will explore the causes, symptoms, diagnosis, and treatment options for myopia, as well as its impact on childhood and progressive myopia.
Physical Optics of Myopia
To understand myopia, it is helpful to understand the physical optics of the eye. The eye has a clear, curved lens that refracts light so that it focuses on the retina, the light-sensitive layer at the back of the eye, which acts like a roll of the camera.
In a normal eye, the lens and other structures in the eye refract light so that it focuses directly on the retina, resulting in clear vision. However, in people with myopia, the cornea or the lens are too curved or are irregular or the eyeball is too long, causing light to focus in front of the retina instead of on it. This results in blurry distance vision. Near vision is generally intact in such eyes.
Causes of Myopia
The exact cause of myopia is largely unknown, but it is thought to be a combination of multiple genetic and environmental factors affecting at the same time.
Children with one or both parents with myopia or myopic astigmatism, are more likely to develop myopia themselves.
With the rise of the internet, digital exposure has increased by leaps and bounds, especially with Covid. Spending a lot of time doing close-up work, like reading, stitching or using electronic/digital devices, and also spending less time outdoors are also thought to contribute.
Other risk factors for myopia include being of Asian descent and having a higher level of education. Living in urban areas is also thought to be a causative perhaps due to more digital use and less availability of open spaces.
Symptoms of Myopia
The main symptom of myopia is difficulty seeing distant objects clearly. Other symptoms may include eye strain, headaches, and squinting.
Children with myopia may have difficulty seeing the board at school or playing sports, and they may have a tendency to sit close to the TV or hold books very close to their face.
Diagnosis of Myopia
Myopia is typically diagnosed during a comprehensive eye exam. The exam includes a visual acuity test, which measures how well you can see at different distances, and a refraction test, which determines the degree of your myopia. The eye doctor may look for signs of other eye conditions. In certain cases the eyes are instilled with dilating eyedrops for examination of the retina.
Treatment Options for Myopia
One way to address myopia in children is to encourage them to spend more time outdoors. Studies have shown that spending time outdoors can help reduce the risk of myopia in children, and may even help slow the progression of the condition in those who already have it.
The goal of treatment is to correct the refractive error so that light can focus directly on the retina, resulting in clear vision.
1. Glasses
Glasses are a common and effective way to correct myopia. Spectacles are a relatively inexpensive and non-invasive option for correcting myopia.
They can be customised to the individual's prescription and preferences, with options for different frame styles, lens materials, and coatings. They also provide a quick and easy solution for those who need vision correction.
They work by adjusting the way light enters the eye so that it focuses correctly on the retina. These lenses are concave or "minus" in shape, meaning they are thinner at the center and thicker at the edges. This shape helps to spread out the light as it enters the eye, allowing it to properly focus on the retina. Glasses can be a good option for people who are not good candidates for other types of treatment, like children or those with severe myopia.
However, some people may find glasses to be inconvenient or uncomfortable, and may prefer other options like high index glasses, contact lenses or refractive surgery. It is important to discuss all available options with an eye doctor to determine the best treatment plan for each individual's unique needs and preferences.
If you use digital/electronic screens, consider using blue-light filters on your glasses.
2. Contact lenses
Contact lenses are a popular option for correcting myopia, as they provide a comfortable and convenient alternative to glasses. Contact lenses work by placing a thin lens directly on the surface of the eye, which refracts light and corrects vision. They can be a good option for people who have an active lifestyle or do not want to wear glasses for aesthetic reasons.
There are several types of contact lenses available for myopia, including soft lenses, rigid gas permeable lenses, and hybrid lenses. Soft lenses are the most common type and are made from a flexible, water-containing material that conforms to the shape of the eye. Rigid gas permeable lenses are made from a harder, more rigid material that allows more oxygen to reach the eye. Hybrid lenses combine elements of both soft and rigid lenses, providing the comfort of soft lenses with the clarity of rigid lenses.
While contact lenses can be a safe and effective option for correcting myopia, it is important to follow proper care and hygiene practices to avoid infections or other complications. This includes washing hands before handling lenses, properly cleaning and storing lenses, and avoiding wearing lenses for longer than recommended.
It is also important to note that contact lenses do not address the underlying causes of myopia, and may not be suitable for everyone. It is important to discuss the pros and cons of contact lenses with an eye doctor to determine if they are the right option for your individual needs and lifestyle.
One can choose the type of lens that suits their life style and visual needs. One can opt for daily disposable, monthly disposable or yearly disposable lenses depending on whether they sparingly need them, need them quite a few times or wear them daily respectively. Multifocal lenses are available which correct distance and near vision. Toric lenses correct astigmatism.
3. Refractive surgery
Refractive surgery is a more permanent treatment option for myopia. There are several types of refractive surgery, based on the target tissue. They include LASIK, PRK, SMILE, refractive lens exchange (RLE) and Implantable Collamer Lenses (ICL). These procedures either work by reshaping the cornea, the clear, dome-shaped surface at the front of the eye, so that light can focus correctly on the retina or an appropriate lens is introduced inside the eye as in RLE or ICL. Refractive surgery is generally considered safe and effective, but it does carry some risks and is not suitable for everyone.
LASIK (Laser-Assisted In Situ Keratomileusis)
LASIK is a popular refractive surgery procedure used to correct myopia. During the procedure, a thin flap is created on the cornea using a microkeratome or femtosecond laser. The flap is then lifted, and an excimer laser is used to reshape the underlying cornea to correct the refractive error. The flap is then replaced and allowed to heal.
LASIK is generally a safe and effective procedure, with a high success rate. Most patients experience improved vision immediately after the procedure, with minimal downtime required for recovery. However, there are some potential risks and side effects associated with LASIK, such as dry eyes, glare, halos, and reduced night vision.
PRK (Photorefractive Keratectomy)
PRK is a type of laser eye surgery used to correct myopia. In PRK, the outer layer of the cornea is removed to access the underlying tissue, which is then reshaped using a laser to improve vision.
Unlike LASIK, which involves creating a flap in the cornea, PRK involves removing the entire outer layer of the cornea. This can result in a longer recovery time, as the eye needs time to regenerate the removed tissue. However, PRK can be a good option for people who have thin corneas or other factors that make them unsuitable for LASIK.
SMILE (Small Incision Lenticule Extraction)
SMILE is a type of refractive surgery used to correct myopia and astigmatism. It is a minimally invasive procedure that involves using a femtosecond laser to create a thin, disc-shaped piece of corneal tissue called a lenticule, which is then removed through a small incision in the cornea.
Unlike other forms of refractive surgery, such as LASIK and PRK, SMILE does not involve creating a corneal flap. This means that the procedure is generally quicker and has a shorter recovery time, with patients experiencing less discomfort and a lower risk of complications.
RLE (Refractive Lens Exchange)
Refractive lens exchange (RLE) is a surgical procedure that involves replacing the natural lens of the eye with an artificial lens in order to correct refractive errors such as myopia, hyperopia, and presbyopia. This procedure is typically recommended for patients who are not good candidates for LASIK or other laser vision correction surgeries.
During RLE, the natural lens of the eye is removed and replaced with an intraocular lens (IOL) that is selected based on the patient's individual needs and vision goals. The IOL can be monofocal, multifocal, or accommodative, and is typically chosen to provide the best possible vision correction for the patient.
RLE is a safe and effective procedure that can provide long-term vision correction for patients with refractive errors. However, like any surgical procedure, it does carry some risks
Implantable Collamer Lenses (ICLs)
ICLs are a type of surgical option for correcting refractive errors, including myopia. They are a type of contact lens that is implanted inside the eye, specifically between the iris and the natural lens. ICLs are made of a biocompatible material called collamer, which is designed to mimic the natural lens of the eye and provide clear vision.
ICL surgery is a relatively quick and painless procedure that is typically performed under local anesthesia. The surgeon makes a small incision in the cornea and inserts the ICL into the eye. The lens is then positioned in the correct location between the iris and the natural lens, and the incision is closed. Patients are typically able to return to their normal activities within a few days of the procedure.
ICLs offer several advantages over other surgical options for correcting myopia. Unlike LASIK and PRK, which involve reshaping the cornea, ICLs do not alter the natural shape of the eye. This can be particularly beneficial for those with thin corneas or other corneal abnormalities that make them poor candidates for other types of refractive surgery. ICLs also provide excellent visual outcomes, with many patients achieving 20/20 vision or better after the procedure. However, like any surgical procedure, ICL surgery does carry some risks
What is Progressive Myopia?
Progressive myopia is a form of nearsightedness that worsens over time, and can be particularly concerning for children. With the rise of online teaching and increased screen time due to the COVID-19 pandemic, many children are spending more time indoors and potentially at risk for developing myopia.
Studies have shown that spending time outdoors can help reduce the risk of myopia in children, and may even help slow the progression of the condition in those who already have it. However, with the current situation, it can be challenging for parents to encourage their children to spend time outdoors.
In addition to spending time outdoors, it is important for parents to monitor their children's screen time and ensure they take regular breaks to rest their eyes. Parents can also encourage healthy lifestyle habits like eating a balanced diet and getting regular exercise, which can help promote overall eye health.
If a child is diagnosed with progressive myopia, it is important to work closely with an eye doctor to monitor the condition and adjust treatment as necessary. Glasses and contact lenses are the most common options for correcting myopia, but there are also several surgical options available for those who are eligible.
What is Pseudomyopia?
Pseudomyopia is a condition where the eye temporarily exhibits nearsightedness or myopia, even though the refractive power of the eye is normal. This condition can occur due to a number of factors, including fatigue, stress, and prolonged use of digital screens.
Unlike true myopia, which is caused by a structural problem in the eye, pseudomyopia is a functional issue that can often be corrected with rest, relaxation, and eye exercises. In some cases, eye drops or other medications may be used to alleviate symptoms. While pseudomyopia is generally a temporary condition, it is important to seek medical attention if symptoms persist or if there are other underlying eye conditions that may be contributing to the problem.
Can myopia be prevented?
True myopia cannot be prevented, however, its rate of progression may be reduced. Preventing myopia starts with adopting healthy lifestyle habits, particularly for children. Here are some tips that can help reduce the risk of developing myopia:
Spend time outdoors: Encourage children to spend at least 2-3 hours a day playing outside or engaging in outdoor activities. Studies have shown that spending time outdoors can help reduce the risk of myopia.
Limit screen time: Too much screen time can strain the eyes and increase the risk of developing myopia. Encourage children to take regular breaks and limit their screen time.
Maintain good posture: Poor posture can strain the eyes and contribute to myopia. Encourage children to sit up straight and maintain good posture while studying or using electronic devices.
Take regular eye breaks: Encourage children to take a break every 20 minutes and look away from their screens or books to rest their eyes.
Get regular eye exams: Regular eye exams can help detect myopia and other eye conditions early, making it easier to manage and treat.
By adopting these healthy habits, we can help reduce the risk of developing myopia and protect our vision for the long term.
In summary, myopia is a growing concern in India and around the world. While there are several treatment options available, it is important to take steps to prevent the condition from developing in the first place, particularly in children. By raising awareness about the risks of myopia and encouraging healthy lifestyle habits, we can help protect our vision and prevent the spread of this increasingly common condition.
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