What is myopia, astigmatism and hyperopia or presbyopia?
Differences between myopia, astigmatism and hyperopia
We will show you the main differences, what the causes are, why they occur, how people who suffer from these visual problems see, and what things could make them worse.
After reading this guide on the 3 main visual problems suffered by people who use optical lenses to correct their vision, you will be able to talk to anyone about the subject in a relaxed manner.
But above all, after reading this guide we hope you can prevent and not cure, there are many things that increase the diopters of ophthalmological prescriptions to correct the vision of people with astigmatism, myopia and hyperopia.
The three pathologies are caused by a defect in the refraction of the image on our retina. In simple terms, it is because our eye is not perfect and over time it becomes deformed and the image is formed in places other than our focus of vision.
There are exercises and techniques to take care of our vision. Remember that the eyeball is a muscle and if we do not take care of it we will have to use increasingly more corrective lenses, which are more expensive and heavier.
Some people are born with their eyeballs having myopia, astigmatism and hyperopia and these exercises can help prevent this from gradually increasing.
- What is the highest level of myopia that exists?
- How does a nearsighted or nearsighted person see?
- What is myopia?
- What causes myopia?
- What are the symptoms of myopia?
- How can myopia be eliminated or corrected and what type of lenses are used?
- What causes myopia to increase?
- When and how is myopia stopped?
- What types of myopia exist?
- What happens if you don't wear glasses to correct myopia?
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Everything you need to know about Astigmatism
- What is the highest level of astigmatism that exists?
- How does a person with astigmatism see?
- What is astigmatism and why does it occur?
- What types of astigmatism exist?
- Why does astigmatism occur?
- What are the symptoms of astigmatism?
- What happens if you don't wear glasses to correct astigmatism?
- What type of lenses and what is used to correct astigmatism?
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Everything you need to know about Hyperopia and Presbyopia
- What is the vision of a person with hyperopia?
- What is hyperopia?
- How can presbyopia be prevented?
- Why does hyperopia or presbyopia occur?
- Is hyperopia the same as presbyopia?
- When does presbyopia or hyperopia stabilize?
- What type of lenses are used to correct farsightedness?
Before defining each of the refractive problems for which people commonly use optical lenses, we will show you what is the highest level of myopia and astigmatism corrected with optical lenses, and how a person who suffers from myopia, astigmatism or hyperopia sees life and letters.
What is the highest level of astigmatism and myopia? We show you the Guinness record.
Empirically we have seen ophthalmological prescriptions for people with up to -24.00 in myopia combined with astigmatism -6.00
Today there is no formal record, but there is a Guinness record for the correction of myopia combined with astigmatism.
In February 2016, scientists from France and Slovakia joined forces to correct myopia -106.00 with astigmatism 6.00.
How does a nearsighted person or a person with myopia see?
People who suffer from this problem see nearby objects clearly, although they do not perceive things that are far away clearly. They perceive things that are far away in a blurry way and have problems focusing on objects. Their vision is slightly sharp, although there are cases in which they see things completely blurry.
What is the vision of a person with hyperopia?
This is the downside of myopia. A person with hyperopia sees distant objects clearly but does not perceive objects clearly and cannot read letters that are close up.
How do people with astigmatism see letters?
People with astigmatism see letters on top of each other or off-axis, depending on the degree of astigmatism the person has.
Myopia
What is myopia?
Myopia is an optical defect that occurs when light rays coming from an object are focused and formed in front of the retina, when in reality they should be focused behind it. This causes the image to appear out of focus and spherical in surface; a myopic person sees blurred images of objects that are far away.
What causes myopia?
Myopia usually occurs when the eyeball is longer than normal or when the curvature of the cornea is too pronounced .
The prevalence of myopia increases in people with higher education or who work in front of a computer, due to the effect of proximity to the eyes caused by intense reading work . It is also more frequent in people of oriental race.
There is also a genetic tendency , although there is great heterogeneity in the genes involved. Therefore, we cannot speak of inheritance from a single gene (monogenetic) but rather of a multifactorial origin, with the influence of several acquired factors that are also important.
On the other hand, there are cases of myopia induced by the increase in dioptric power of the lens, which occurs in elderly subjects with cataracts.
Diabetes can also be a disease that tends to cause myopia, due to the osmotic effect of excess glucose in the lens. Other risk factors for this refractive error are drugs such as corticosteroids, sulfonamides, carbonic anhydrase inhibitors.
What are the symptoms of myopia?
The typical symptom of myopia is blurred vision in the distance . There is also nocturnal myopia, which worsens at night due to the effect of pupil dilation.
The incidence of myopia varies according to the reference population, but in developed countries it is estimated that Myopia affects 20% of young people.
How can myopia be eliminated or corrected and what type of lenses are used?
Optical correction with divergent or biconcave lenses is the primary and first treatment for myopia. That is, the use of glasses that are suitable and graduated according to the patient's diopters.
To do this, if a person notices that they suffer from blurred vision at a distance, difficulty distinguishing things, people, letters or numbers from a certain distance, they should go to the ophthalmologist for an eye exam.
On the other hand, corneal refractive surgery (LASIK ) is currently a safe procedure and can correct myopia of up to 6 diopters, hyperopia of up to 5 diopters and low regular astigmatism.
Likewise, in adults over 50 years of age with severe refractive errors and presbyopia, the implantation of intraocular lenses is an option, although the risks must be taken into account.
What causes myopia to increase?
The eye is a muscle, in general myopia increases due to genetic factors or degeneration factors. Remember our free eye health guide that you can use to find out more about how to rest your eyes properly. Download it for free at this link
Working at short distances
People who do an excessive amount of near vision work may experience false myopia, or "pseudomyopia." Blurry distance vision is usually caused by overuse of the eyes' focusing mechanism.
After a long period of working at close range, the eyes have difficulty refocusing and seeing clearly in the distance, although vision usually returns after rest. However, constant visual stress can lead to a permanent reduction in distance vision over time.
Time spent outdoors
Several studies have highlighted the association between time spent outdoors and a lower likelihood of myopic refraction. The main idea behind this factor is that myopia improves due to higher light levels, greater depth of focus and increased dopamine release.
A similar beneficial effect of physical activity on myopia has also been described.
Other conditions
Symptoms of myopia can also be, for example, a sign of fluctuations in blood sugar levels in people with diabetes or an early indication of a developing cataract. Therefore, those with pre-existing conditions should pay more attention to their condition, as it can affect the quality of their vision.
When and how is myopia stopped?
There is increasing evidence that They point out that practicing outdoor activities during childhood reduces the incidence of myopia and slows its progression .
Also, given the effect that visual deprivation has on increasing myopia, It is advisable to increase ambient lighting, both direct and indirect, at home or at work , in order to ensure good vision and prevent the eye from overexerting itself. In addition, although the effect of accommodation on myopia has not been proven, frequent rest when performing close-up visual activities is recommended.
Remember our free eye health guide that you can use to find out more about how to rest your eyes properly. Download it for free at this link
What types of myopia exist?
Simple myopia : This is less than 6 diopters and generally does not present complications.
High myopia : Also called degenerative myopia, greater than 6 or 8 diopters and with a greater predisposition to cause complications and have other associated ocular pathologies. In general, the greater the number of diopters, the greater the risk of complications. Very high myopia is also called high myopia.
What happens if you don't wear glasses to correct myopia?
When a person with myopia who needs optical lenses does not wear them, his relationship with the environment is less effective, his actions become clumsy, he may develop visual problems and also health problems. Here are some examples:
Uncorrected myopia can cause lazy eyes. Myopic people who do not wear glasses may suffer from constant tearing, headaches, eye irritation, and other visual discomforts.
Not wearing glasses can make your myopia problem worse because you are straining your eyes to see clearly and causing the myopia to get bigger in the effort to try to focus on objects or letters. This is why we recommend wearing glasses with your ophthalmological prescription.
Astigmatism
What is astigmatism and why does it occur?
Astigmatism is a common problem that can make vision blurry or distorted . It occurs when the cornea (the clear layer at the front of the eye) or lens (an inner part of the eye that helps focus) is abnormally shaped.
What types of astigmatism exist?
Before we can explain the types of astigmatism that exist, we must first explain what meridians are. To understand what meridians are, think of the front of your eye as a clock. A line connecting 12 to 6 would be one meridian, while a line connecting 3 to 9 would be the other.
There are three primary types of astigmatism:
- Myopic astigmatism. One or both of the principal meridians of the eye focus as myopic. If both meridians focus as myopic, they do so to different degrees.
- Hyperopic astigmatism. One or both principal meridians focus hyperopicly. If both focus hyperopicly, they do so to a different degree.
- Mixed astigmatism. One principal meridian focuses as myopic, and the other as hyperopic.
Astigmatism is also classified as regular or irregular. In regular, the principal meridians are perfectly perpendicular to each other (they form a 90-degree angle). In irregular astigmatism, they are not perpendicular. Most astigmatisms are regular corneal, meaning the front surface of the eye is shaped like a football.
Irregular astigmatism can be the result of an injury to the eye that caused scarring of the cornea, surgery, or keratoconus, an eye condition that causes thinning of the cornea.
Why does astigmatism occur?
With astigmatism, the eye becomes egg-shaped or oval, like an American football. There are two basic types of astigmatism:
- Horizontal Astigmatism (when the eye is wider than it is tall) and
- Vertical Astigmatism (when the eye is taller than it is wide).
With any of these types of astigmatism, near and far vision is blurry due to the irregular shape of the eye.
Astigmatism is very common. Doctors don't know why the shape of the cornea or lens varies from person to person. But they do know that the risk of astigmatism is inherited (passed down from parents to children).
People can also have astigmatism from:
- Eye Disease
- Eye Injury
- Or after surgery
It is a myth that astigmatism can occur or worsen from reading in dim light or sitting too close to the television.
What are the symptoms of astigmatism?
Symptoms of astigmatism may include:
- blurred vision or areas of distorted vision;
- eye strain;
- headache;
- squint to see more clearly; or
- eye discomfort.
These symptoms don't necessarily always mean you have astigmatism. To find out what's causing your symptoms, visit an eye doctor for a complete eye exam.
Children may not realize that they have blurred vision . They are unlikely to complain of blurred or distorted vision.
But without treatment, astigmatism can:
- Affect a child's performance in school and sports.
- Produce amblyopia (lazy eye) and vision loss.
That's why eye exams in the early years, whether performed by a pediatrician, family doctor or other eye care professional, are so important. If astigmatism or another eye problem is found, consult an ophthalmologist for proper treatment.
What happens if you don't wear glasses to correct astigmatism?
A person with astigmatism who needs to wear glasses and does not wear them, may experience headaches, dizziness, in general the person becomes more clumsy as his relationship with his environment becomes less effective, his actions become clumsy, he may develop visual problems and also health problems. Here are some examples:
Astigmatism that is not corrected with optical lenses can cause your eye to work harder than necessary to focus. If you have astigmatism and do not wear lenses, you may experience constant tearing, headaches, eye irritation, and other visual discomforts.
What type of lenses and what is used to correct astigmatism?
Astigmatism is corrected by using toric lenses or crystals, also known as cylindrical lenses, which are characterized by having two curvatures, the horizontal axis being flatter, and the vertical axis being more pronounced.
Astigmatism can often be associated with other types of vision problems such as hyperopia and myopia. Astigmatism is corrected by wearing glasses or cylindrical (concave or convex) monofocal contact lenses, depending on which part of your eye the light is projected onto.
The corrective glass or lens used in your optical lenses will have different thicknesses depending on the area of the lens. It is also advisable to reduce the glass so that the aesthetic effect is optimal, in diopters over 3.00 you could choose a thinned organic glass with an index of 1.61 or 1.67.
Hyperopia or Presbyopia
What is hyperopia?
Hyperopia, also known as presbyopia, farsightedness or tired eyes syndrome, is the condition in which nearby objects appear blurry and from a certain distance they appear sharper. This is because the size of the eye is a little shorter than normal or we have simply aged and our eye is taking its toll on us.
It is also common for the patient to have a cornea that is flatter than it should be. As a result, near vision is not clear because the light rays converge at a point beyond the retina. So the image formed on the retina is not well focused.
How can presbyopia be prevented?
Simple, by taking breaks and following the rules of visual exercises for 20-20 vision. The eyeball becomes lazy and does not focus at the distances it should focus on. Many times it is due to abusing the focus at certain distances. The ideal is to maintain a balance between natural light and focusing distances.
Give your eyes a break for 20 seconds every 20 minutes and look at objects further than 20 meters. It's not that complicated, remember, look 20-20-20. 20 minutes - 20 seconds at 20 meters. There you go, you've learned it!
Why does hyperopia or presbyopia occur?
The Hyperopia is a very common defect ; in fact, most people are born with physiological hyperopia. Typically, the problem disappears as our visual system develops.
However, as we age we lose the ability to accommodate, specifically after the age of forty. If our eye is farsighted, even if we have a low prescription, we will have no choice but to look for a solution to correct hyperopia .
During childhood or adolescence Children with hyperopia can compensate for this refractive defect through accommodation . In other words, their lens can make an effort by changing its shape in order to see clearly. However, this constant effort has its consequences, causing headaches, visual fatigue and affecting their academic performance.
Is hyperopia the same as presbyopia?
They are different words but they reflect the same thing. The difference is that hyperopia can be attributed to congenital defects and presbyopia to age or to tired eye syndrome.
When does presbyopia or hyperopia stabilize?
Presbyopia usually progresses slowly until the age of 60, when it tends to stabilise, and in addition to blurred near vision, it can cause eye fatigue and headaches. It progresses more rapidly in the first few years and then slows down.
What type of lenses are used to correct farsightedness?
Hyperopia is corrected by using convergent lenses , either optical glasses or contact lenses. If you are going to use contact lenses, we recommend those that can be used more than once, thus reducing your carbon footprint.
Types of refractive surgery or laser eye operations for myopia, astigmatism or hyperopia
In general, this type of laser surgery is performed when the patient has +5.00 to -15.00 diopters in their eyes.
In this video we show you 3 types of laser eye surgeries and correction of myopia, astigmatism or hyperopia.
