Refractive errors are common eye conditions that can cause blurred vision and other symptoms. Comprehensive eye exams can help detect eye conditions like refractive errors, and your optometrist can help you achieve clear vision.
Myopia and astigmatism are two of the most common refractive errors. While they share some similarities, they are two different conditions.
This blog will review the differences between myopia and astigmatism, their causes, symptoms, and treatment options.
Refractive errors are vision problems that make it difficult to see clearly. They occur when light entering the eye does not focus (refract) properly onto the retina.
The eye’s ability to refract or focus light sharply on the retina is primarily based on the overall length of the eye, the curvature of the cornea, and the curvature of the lens inside the eye.
The cornea and lens work together to focus light on the retina. However, if an eye is too long or too short, or the cornea is too steep or too flat, the light isn’t bent properly and won’t land on the correct spot on the retina. It causes images to appear blurry.
4 common types of refractive errors include:
- Myopia (nearsightedness)
- Hyperopia (farsightedness)
Astigmatism is a vision condition that can cause blurry sight at varying distances. It occurs when the clear cornea or the lens of the eye has an irregular shape instead of being perfectly round like a soccer ball.
Causes of Astigmatism
The causes of astigmatism may be hereditary and present at birth, or acquired due to eye injury, surgery, or the relatively rare condition keratoconus, where the cornea thins and forms a cone-like shape. The severity of astigmatism can also fluctuate over time.
Symptoms of Astigmatism
Common symptoms of astigmatism can include:
- Blurred or distorted vision at all distances
- Poor night vision
- Double vision in one or both eyes
Treatment of Astigmatism
There are several treatment options available for managing and correcting astigmatism.
- Eyeglasses are perhaps the most common and simple solution.
- For those who prefer contact lenses, special toric lenses are designed to help correct astigmatism by compensating for the uneven curvature of the cornea or lens.
- A more permanent treatment option is refractive eye surgery, which can reshape the cornea to correct the cause of astigmatism.
It is essential to consult with an eye care professional to determine the best treatment option for your specific circumstances.
Myopia, also known as nearsightedness, is a prevalent visual condition affecting nearly one-third of Canadians. Typically, myopia emerges during childhood and advances until the individual reaches their late 20s.
Causes of Myopia
Myopia arises from an elongated eyeball or a cornea that is too curved. The cornea is responsible for bending and directing light to the retina, where it is converted into visual information. However, when the eyeball is longer than the focal distance of the cornea, light lands in front of the retina, ultimately leading to blurred vision at a distance.
Symptoms of Myopia
Myopia can present itself through a unique set of symptoms. Specifically, individuals with this condition will experience clear vision when looking at objects that are close by, while objects further away appear blurry. It can create quite a challenge when viewing things such as whiteboards, television screens, or movie screens.
The best course of action for diagnosis is to undergo a comprehensive eye examination with an optometrist. During this exam, your optometrist performs specific tests to determine whether or not a prescription for myopia is required.
While glasses, contact lenses, and refractive eye surgery are used to correct blurry vision from myopia, new approaches have also been developed to keep it from getting worse.
- Diluted atropine eye drops are effective in slowing down myopia progression in children and teens.
- Specialty glasses lenses like MiYOSMART offer a unique defocusing technique to change how light focuses on the retina. This both corrects the blurry distance vision from myopia and reduces the tendency for it to get worse.
- MiSight contact lenses have concentric rings of defocus that focus peripheral light in front of the retina, which also provides clear vision while simultaneously slowing down myopia progression.
Book an Eye Exam for Improved Vision and Comfort
With multiple treatment options available today, it’s important for people with any type of refractive error to have regular visits to the optometrist. In addition to keeping you seeing clearly, these appointments help identify other conditions or vision impairments that may need to be addressed. Your optometrist can recommend solutions that improve your visual acuity and comfort.