Eye Conditions
eye conditions

Myopia

Myopia, also known as near-sightedness and short-sightedness, is a condition of the eye where the light that comes in does not directly focus on the retina but in front of it, causing the image that one sees when looking at a distant object to be out of focus, but in focus when looking at a close object.

What Causes Myopia?

Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina, rather than directly on its surface.

Nearsightedness also can be caused by the cornea and/or lens being too curved for the length of the eyeball. In some cases, myopia is due to a combination of these factors.

Astigmatism

Astigmatism is an optical defect in which vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image on the retina.

What Causes Astigmatism?

Astigmatism usually is caused by an irregularly shaped cornea. Instead of the cornea having a symmetrically round shape (like a baseball), it is shaped more like a football, with one meridian being significantly more curved than the meridian perpendicular to it.

Hyperopia

Hyperopia commonly known as being longsighted is a defect of vision caused by an imperfection in the eye causing difficulty focusing on near objects, and in extreme cases causing a sufferer to be unable to focus on objects at any distance.

What Causes Hyperopia?

This vision problem occurs when light rays entering the eye focus behind the retina, rather than directly on it. The eyeball of a farsighted person is shorter than normal.

Presbyopia

Presbyopia is a condition associated with aging in which the eye exhibits a progressively diminished ability to focus on near objects.

What Causes Presbyopia?

Presbyopia is caused by an age-related  process. This differs from astigmatism, nearsightedness and farsightedness, which are related to the shape of the eyeball and are caused by genetic and environmental factors. Presbyopia generally is believed to stem from a gradual thickening and loss of flexibility of the natural lens inside your eye.

These age-related changes occur within the proteins in the lens, making the lens harder and less elastic over time.

Age-related changes also take place in the muscle fibers surrounding the lens.
With less elasticity, the eye has a harder time focusing up close.

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