Do you know enough about astigmatisms and presbyopia

Eye problems become a natural part of life as you age or spend time in front of screens, so no need to fret: learn about astigmatisms and presbyopia to arm yourself with defense.

Astigmatism means that the shape of the eyeball is distorted, and is longer in one direction than another, rather like a football. This means that either the cornea or, less often, the lens, is not smoothly curved like the surface of a Ping-Pong ball, as it should be.

• The irregular curvature means that light entering the eye is bent more in one direction than another. Light rays do not come to a focus at a single point but produce two or more focal points, so only part of an image is in focus at any time.
• This makes images appear blurred or wavy.  Astigmatism can occur with far or nearsightedness, and most people have it to some degree.
• If it's mild, it does not need treatment. If you are experiencing blurring for near and distant vision, or any other symptoms — such as squinting, eyestrain or fatigue when doing close work — you need to get your eyes tested.
• If you are found to have astigmatism and you do a lot of driving or spend long hours in front of a computer, you will probably need some form of corrective lenses. The condition can be hereditary and is frequently present from birth. Like farsightedness, it tends to get worse with age.
• It can also develop with some eye diseases or following injury or surgery; it could even be caused by habitually adopting an asymmetric posture or reading at an angle.
• Sometimes, a cyst on the eyelid causes astigmatism; in this case, once the cyst clears up then so does the astigmatism.

By the time we reach 60, most of us will need reading glasses for a condition called presbyopia that makes our near vision less sharp than it once was.

• Scientists think that presbyopia is caused by a combination of thicker, harder, less flexible lenses and less efficient, more lax eye muscles — which makes it harder for our eyes to focus on objects close up.
• Eventually the near point — the closest distance from which the eye can create a sharp image on the retina — is farther away from the eye than the reading distance.
• If you find that you are having to hold books, newspapers and menus at arm's length in order to read what seems like increasingly hazy print, you probably have presbyopia. It is virtually inevitable and usually becomes more noticeable between the ages of 40 and 50.
• It is worse in poor light and improves in sunlight, because pupil narrowing improves focus. Prolonged close work may cause headaches or eyestrain.
• Presbyopia will run its course irrespective of whether you wear glasses; glasses will compensate for the problem rather than contribute to it.