Presbyopia
Presbyopia is what occurs to our eyes as we age and causes a change or a deterioration in near vision. For example, reading fine print becomes difficult.
Presbyopia is often confused with Hypermetropia (long-sightedness) as both cause reduced vision for near/ closeby objects whilst far vision usually remains clear, however they are not the same eye condition.
It is possible to have Hypermetropia and Presbyopia and it is also possible to have Myopia and/or Astigmatism with Presbyopia.
Causes of Presbyopia
When we are young the Crystalline Lens in our eye is very flexible and it changes shape in order for us to focus on things far and near- the lens is in a relaxed state when looking far and contracts when looking near. This is called Accommodation.
Presbyopia is caused by a reduction in the flexibility of the lens which means it is unable to contract and the eye cannot focus well for near objects. This is a gradual age related deterioration which begins at around 40 years old and worsens over time as the lens becomes stiffer and more rigid, however some people experience a very rapid change in their vision once Presbyopia has occurred.
It causes us to develop a separate degree for near/reading vision than what, if any, we need for far/distance vision i.e. the degree we use for seeing far will no longer be the same as the degree we use for seeing near.
Presbyopia with different types of degree
Someone with Myopia has reduced far vision and usually clear near vision. Before the age of 40 (i.e. before presbyopia has occurred) when wearing corrective glasses/contact lenses their vision should be clear for both far and near with the same degree. However once presbyopia has occurred, this is no longer the case and their near vision is reduced whilst wearing their far vision degree.
Someone with Hyperopia may or may not have observed a reduction in near vision before the age of 40 depending on the level of their degree. If glasses/contact lenses are already worn, once presbyopia occurs, this glasses degree may no longer be good enough for near vision and a separate (stronger) degree will now be required for near.
Someone with Emmetropia has likely never experienced blurred vision for far or near vision. Once presbyopia occurs they will have a noticeable reduction in near vision, but far vision should remain unchanged.
How to correct Presbyopia?
There are many options to correct Presbyopic vision and this may differ between each person and their current, if any, spectacle degree:
- Wear near vision degree glasses when doing close vision work. e.g. reading, computer use, remove when looking far
- Wear Multifocal spectacles/contact lenses which contain both far and near vision degrees
- Wear a contact lens in ONE eye with near vision degree whilst the other eye sees far naturally without correction
- Remove far vision degree glasses when reading
- Wear Multifocal spectacles/contact lenses which contain both far and near vision degrees
- Wear a contact lens in one eye with far vision degree and one with near vision degree (if required)
- Have two separate pairs of glasses one with far vision and the other with near vision degree (if required)
- Wear Multifocal spectacles/contact lenses which contain both far and near vision degrees
- Wear a contact lens in one eye with far vision degree and one with near vision degree
- Have two separate pairs of glasses one with far vision and the other with near vision degree
Before making any changes to your glasses/contact lenses it is best to consult an Optometrist and have an eye examination to properly check for Presbyopia and prescribe an appropriate degree. It is not advised to change/presbrice a glasses or contact lens degree without first having it checked with an eye care professional.
