What Is Presbyopia?
Presbyopia is the gradual reduction in the amount that the eye can change its focus. The changes are the result of the continued growth of the biological lens inside the eye, and are a normal part of ageing. Presbyopia usually becomes noticeable between the ages of 40 and 50 as an inability to focus on near objects. People in this age group often find that they have to hold things further away to see them clearly.
How Will Presbyopia Affect My Vision?
Close tasks such as reading and sewing become difficult, particularly in poor light. For example, you may find that you are holding your newspaper further away from your eyes to make the print clearer. Presbyopia does not affect distance vision, however you may find you are slower to readjust to clear distance vision after reading. You may also have difficulty concentrating when reading or you may find periods of close work result in sore eyes, headaches or tiredness.
What Causes Presbyopia?
It is important to understand how your eyes change their focus for viewing close objects. Normally they are focused for distance vision. Inside the eye there is a lens about the size of a pea. To focus on close objects, a special muscle in the eye changes the shape of the lens. This process is called accommodation. With age the lens loses its flexibility and is less able to change its shape. This is a completely normal ageing change, just like stiffening joints or greying hair. The loss in lens flexibility is the reason that close focusing becomes more difficult. Everyone experiences the ageing process that causes presbyopia. The condition cannot be prevented.
Presbyopia is usually first noticed around the age of 40 to 45 years. Although difficulties with close work may seem to come on suddenly, the ageing process that causes presbyopia is gradual and has been going on since childhood. Between the ages of 45 and 65, the amount of presbyopia increases, making near work more difficult. From 65 years onwards, there are unlikely to be any further significant changes to vision due to presbyopia.
How Is Presbyopia Treated?
Presbyopia is corrected by a prescription designed especially for close distances, in the form of spectacles or contact lenses. It is important that the prescription is calculated for the distance at which you do your close tasks. Through discussion with your optometrist, you will be able to decide on the best way of preparing your prescription. The correction for presbyopia will make near objects clear but distant objects blurry. This means that if you have a pair of spectacles just for reading, you will not be able to watch television while wearing them. You can be prescribed multifocals which will allow vision at all distances. Presbyopia does not represent a threat to your eyes’ health.
Will Wearing Spectacles Weaken My Eyes?
No. Presbyopia will continue regardless of whether spectacles are worn. Wearing spectacles will not accelerate or slow the development of presbyopia.