What is the difference between Myopia and Astigmatism?
Table Of Contents
What is the difference between myopia and astigmatism? How does a person with astigmatism and myopia see? What causes myopia and astigmatism?
Is it possible to have myopia and astigmatism together? That is, to have astigmatism and myopia at the same time. If so, how does a person with myopia and astigmatism see? In this blog post we will explore all of the above!
We have been asking ourselves all these questions and that is why we have created today’s article, to help you clarify all these doubts and be clear about the difference between myopia and astigmatism.
So, let’s start at the beginning:
What is the difference between myopia and astigmatism?
The difference between myopia and astigmatism is that myopia causes objects far away from us to focus in front of the retina instead of focusing on the retina.
In the case of astigmatism, when focusing on an object, the light is not focused on a particular place on the retina, but there is more than one point of focus.
Now that we know the difference between myopia and astigmatism let’s see what each means in more detail.
What is Myopia? What is Astigmatism?
Myopia and astigmatism are two refractive defects that do not allow good visual acuity; they can be related but are not the same.
What is Myopia or Nearsightedness?
Myopia is a refractive error that occurs when we cannot see objects far away from us.
This may be due to:
- Our eye is more elongated than it should normally be.
- Or because the eye has a higher refractive power than usual.
In this situation, the image is created in front of the retina instead of on the retina.
Myopia usually appears in childhood and stabilizes in adolescence (up to 21 years of age).
What is astigmatism?
Astigmatism, on the other hand, is also a refractive error, but it occurs when the curvature of the cornea is altered.
That is, instead of being spherical, in the case of astigmatism, the cornea is more asymmetrical and may have a more oval shape.
This fact causes the light, instead of focusing on one point on the retina, to focus on more than one point, which triggers distorted and blurred vision, both near and far.
Astigmatism can appear at any age.
The main difference between myopia and astigmatism is that the person with myopia sees distant objects blurred, and the person with astigmatism sees both near and distant objects blurred.
What causes myopia and astigmatism?
Myopia occurs when the eyeball is too long or when there are problems with the shape or condition of the cornea or lens, which causes the light to not focus properly through the eye.
Astigmatism is a very common refractive defect produced because the cornea’s curvature is irregular. The reason why this may be variable is unknown, but it is known that astigmatism can be hereditary. That is, it can be inherited from parents to children.
Astigmatism may also be due to an eye injury, disease, or after surgery.
Is it possible to have astigmatism and myopia at the same time?
Yes, it is possible to have myopia and astigmatism together. Astigmatism can occur alone or together with another refractive defect, such as myopia or hyperopia.
How do you describe having astigmatism and myopia together?
Having astigmatism and myopia at the same time is referred to as Myopic astigmatism.
As we’ve mentioned previously, both myopia and astigmatism are two refractive errors due to a difference in corneal power, and they can occur simultaneously.
At the same time, we can differentiate between two types of myopic astigmatism depending on the point and degree of light focusing on the retina.
We refer to simple myopic astigmatism, which is when one eye axis focuses objects in front of the retina and the other axis on the retina.
Compound myopic astigmatism is when both axes of the eye focus the light in front of the retina but at different degrees.
Maximum correction for Myopia and Astigmatism?
The maximum diopters that can be corrected for myopia are up to 25 diopters and up to 13 diopters for astigmatism.
Considering that in myopia, the diopter will be negative, and a divergent lens will be used to move the image away from the retina (remember that a myopic person focuses in front of the retina).
In the case of astigmatism, the cylinder value can be either negative or positive, depending on whether it is myopic or hyperopic astigmatism.
It will be accompanied by the axis, expressed in degrees ranging from 1° to 180°, indicating where the astigmatism is.
But what happens if we do not correct myopia and astigmatism?
What happens if I have myopia and astigmatism and I don't wear glasses or contact lenses?
If we have myopia and astigmatism and do not wear glasses, we will not correct the optical error; therefore, our vision will continue to be blurred.
In addition, we may suffer other consequences of these refractive defects, such as headaches, stumbling, fatigue, eye irritation, and tearing, among others, not to mention that we can jeopardize both our safety and that of others when driving.
If we suffer from myopia and astigmatism and do not want or cannot wear glasses, we can try other effective methods, such as contact lenses or surgery, if we are suitable for it.
Our trusted optometrist or ophthalmologist will be the best person to advise us and assess the best option for our particular case.
What do you see when you have myopia and astigmatism at the same time?
As we indicated before, a person with myopia sees distant objects distorted or blurred, and someone with astigmatism sees both distant and near objects distorted or blurred.
Therefore, a person with both myopia and astigmatism will have difficulty seeing objects at any distance.
Conclusions on the difference between myopia and astigmatism
To summarize, myopia and astigmatism are two refractive errors, but they are different.
When a person is myopic, they do not see distant objects clearly; when a person has astigmatism, they do not see distant or near objects clearly.
In myopia, the axial length of the eye is longer, while in astigmatism, the cornea or lens is asymmetrical.
This means that in the case of myopia, the focus is in front of the retina (instead of on the retina), and in the case of astigmatism, the focus is on more than one point of the retina.
While myopia appears at an early age and usually stabilizes in adolescence, astigmatism can appear at any age.
However, although both visual defects (myopia and astigmatism) can develop separately, it is also possible to have myopia and astigmatism together.
And what does it mean to have myopia and astigmatism at the same time? It means that the person has myopic astigmatism and will have problems focusing both far and near.