When you are looking at something that is far away, your eye – if you are perfect sighted – is shaped so that the object is clearly focused on your retina. This means that the image is clear. When you look at something close up, for example to read a book, the muscles inside your eye that surround the lens contract to make the lens change shape and this focuses the light from the book onto your retina.
The lens inside a child’s eyes is elastic, and so can change shape easily to enable them to change focus from looking at something far away to looking at something close up. As we get older, however, the lens naturally stiffens and so it changes shape less easily. This means that the distance up to which we are able to focus gets further away and we are no longer able to focus on things that are close to us, having to hold them further away to see them clearly. This is more noticeable when we want to look at something very close to us, such as when threading a needle. It may also mean that it may take longer for us to focus from looking at something close up to looking at something far away (or vice versa).
This change in focusing tends to become more noticeable when we reach our late thirties or forties as we then find it difficult to focus on things that are at the normal reading distance. It is quite common to see people who are presbyopic holding things away from them in an attempt to see them clearly. As this affects things that are close to you first, your vision of things that are further away – such as the computer – is not affected until later, when your lens has lost almost all of its elasticity.
Because the lens has lost its elasticity, when you are presbyopic you will need glasses to focus on the different distances you need to see. This may mean having separate pairs for distance and reading and maybe for middle distance such as looking at the computer or reading sheet music.
What is the treatment for presbyopia?
Presbyopia is a natural part of ageing and there is no cure for it. The solution is generally to wear glasses for reading. Because reading glasses focus light that comes from objects that are close to you, you will find that if you wear them and look at something far away, it will appear blurred. This is quite normal, and you will often notice people peering over their reading glasses to see clearly in the distance. If you do not want to do this, or prefer not to have a separate pair of reading glasses, the alternatives are bifocal or varifocal lenses.
Bifocal glasses have two separate areas of the lens which are separated by a line: the top part of the lens focuses light from distant objects, and the bottom part of the lens focuses light from near objects. Varifocal lenses work in a similar way to bifocal lenses, but they have no line as the lens gradually changes its focus from top to bottom to allow you to see objects at any distance clearly, simply by moving your head up and down to look through a different part of the lens.
Are there exercises I can do to stop needing reading glasses?
Presbyopia is not caused by muscle weakness but by the lens stiffening as we age.
There are no exercises that can help this.
Will I make my eyes worse by wearing glasses?
No. As presbyopia is caused by the lens stiffening, and not the muscles weakening, wearing glasses will not make your eyes worse. However, you may notice that when you take your glasses off, things appear to be worse without them than they were before you had them. This is simply because you are noticing how clear and comfortable vision should be. Before you had the glasses, you were unaware how blurry your vision really was because it changed slowly over the years. Presbyopia will get worse as you age until you reach your late fifties, when you will have no natural focusing ability left. Unfortunately there is nothing you can do to stop it. A change in focusing tends to become more noticeable when we reach our late thirties or forties.
Can I use off-the-shelf reading glasses?
Readymade reading glasses are designed for temporary reading only and are not suitable for driving. They are only suitable for you if both of your eyes have the same prescription and you have no astigmatism. Research has shown that they are often not made to the same standards as prescription glasses, so we would recommend you have a prescription pair for your ‘main’ pair of reading glasses, although it is okay to have readymade glasses as spares. Even if you use readymade reading glasses it is very important that you see your optometrist for regular eye examinations as people over 40 years of age are more at risk of eye diseases such as glaucoma and age-related macular degeneration.
I don’t want to wear glasses – can I have contact lenses instead?
Yes, it is possible to correct presbyopia with contact lenses too. Correcting presbyopia with contact lenses is more complicated than correcting it with glasses. This is because you can look through different parts of a varifocal lens simply by moving your head or eyes. As contact lenses move with your eye, it is more difficult to do this and correct the focus both for distance and near vision, although varifocal contact lenses are available. An alternative, which works very well for some people, is to correct one eye for distance and the other eye for reading. This is called monovision. We suggest you discuss the various options for contact lenses with your optometrist.
