Science

Difference between Myopia and Hypermetropia

Difference between Myopia and Hypermetropia

Myopia and hypermetropia are two types of eye conditions. They both involve a person experiencing blurry objects from a certain range. Normal eyes form the image of the object on the retina. A person having myopia or hypermetropia sees blurry objects because the image of the object is either in front of or behind the retina.

Myopia Vs. Hypermetropia

The main difference is that a person with myopia condition can see objects that are close quite clearly. Distant objects will always appear blurred. In hypermetropia, the person sees distant objects more clearly than they do close objects.

Distant objects are quite blurred for a person with myopia. On the other hand, the objects are clearer in view for the person who is suffering from hypermetropia.

Comparison between Myopia and Hypermetropia

  • A person who is suffering from myopia happens to see objects that are close with a clear view while the one suffering from hypermetropia sees the distant objects quite clearly.
  • Another name for myopia is near or short-sightedness while another one for hypermetropia is far or distant sightedness.
  • In myopia, there is an increase in the size of the eyeball while the same decreases in the case of hypermetropia.
  • In myopia, the image of the object is normally formed in front of the retina making it clearer from a closer view while it is formed behind the retina in hypermetropia. This is why objects are clearer from a distance.
  • Myopia comes about as a result of two situations which include a hereditary condition or too much exposure to sunlight. Hypermetropia on the other hand comes about because of heredity, high blood pressure, or a weak functioning of the ciliary muscle.
  • The symptoms in a myopic condition include blurred visions of distant objects while a person with hypermetropia complains of blurred vision of close objects.
  • Myopia can be treated with the help of a concave lens while hypermetropia can be treated with the use of a convex lens.
  • In myopia, the focal length of the eye lens decreases while it increases in the hypermetropia condition.

What is Myopia?

Another term used to refer to this condition is nearsightedness. This is a vision condition whereby a person can only see close objects clearly but sees all distant objects with a blur. The image is normally formed in front of the retina for a person with a myopic condition.

Myopic conditions occur due to a few reasons that include heredity, exposure to too much sunlight, or the body’s circadian rhythms. A person with a myopic condition experiences an enlargement of the eyeball.

The focal length of the eye lens decreases in the case of a myopic eye. Other effects of this eye condition include glaucoma, retinal detachment, and cataract.

Myopia can be divided into three types:

  • Low Myopia- In this condition, the refractive error is greater or equal to 3:00 D
  • Moderate Myopia- In this condition, the refractive error is less than 3:00 D
  • High Myopia- There is a less refractive error in this myopic condition. Less than 6:00 D

To correct a myopic eye, you can use a concave lens that increases according to the myopia severity.

What is Hypermetropia?

Another term for this eye condition is far-sightedness. This is a condition where a person can see distant objects clearer than he can see the close ones. In this situation, the image of the object is normally formed behind the retina.

The condition comes about as a result of heredity, high blood pressure, weak functioning of the ciliary muscle, extensive curvature of the eye lens, or elongation of the eyeball.

A person with hypermetropia experiences an increase in the focal length of the eye lens. Other effects of this condition include glaucoma, amblyopia, and strabismus.

There are three types of hypermetropia:

  • Low hypermetropia- The refractive error is greater than or equal to 2.00 D
  • Moderate hypermetropia- The refractive error is less than +2.00 D +5.00 D
  • High hypermetropia- The refractive error is less than +5.00 D

To correct a hypermetropic eye, you can use a convex or converging lens.

Difference between Myopia and Hypermetropia

  • A person with a myopic eye happens to see objects that are closer to them more clearly. On the other hand, a hypermetropic person sees distant objects more clearly. Any object that is close by appears blurred.
  • Myopia can be referred to as nearsightedness while hypermetropia can be referred to as farsightedness.
  • The size of the eyeball always increases for the myopic eye while it decreases for the hypermetropic eye.
  • In myopia, the focal length of the eye lens decreases. However, it will decrease for the person who is suffering from hypermetropia.
  • The image of the object is formed in front of the retina for the person who has a myopic condition while the same image of the object is formed behind the retina for the person with a hypermetropic condition.
  • A few causes of myopia could be hereditary, exposure to too much sunlight, and the body experiencing different circadian rhythms. In hypermetropia, the condition comes about as a result of heredity, high blood pressure, and weak functioning of the ciliary muscle.
  • Distant objects appear blurry for a person who has myopia while the same objects are very clear for a hypermetropic person.
  • You can use a concave lens to treat a myopic condition and a convex lens to treat a hypermetropic condition.

Conclusion

In conclusion, a person that is myopic is only able to see objects that are close to him clearly. If the objects are placed in a distant position, the person will see them but with a blurry vision. The reason behind this is that the image of the object is placed in front of the retina.

A hypermetropic person on the other hand will see objects that are far off with a clear vision. The reason behind this is that the image of the object is formed behind the retina.

Both eye conditions can be corrected using different types of lenses. That is, concave for myopia and convex for hypermetropia.