As we get older, the lens within the eye starts to lose its ability to change its shape in order to alter its focus from distance vision to close vision. This natural ageing process is called presbyopia and it is unavoidable I’m afraid.
It can come as quite a shock to some patients in their early/mid forties. It can have two important effects on your vision depending on your type of prescription.
Firstly (most patients), you will find during middle age that it becomes harder to focus on near objects or to read for long periods of time. So you will need reading glasses, or, if you already wear glasses, you will need bifocals or varifocals. If you already wear contact lenses you will now need to wear reading glasses on top of your contact lenses. All very frustrating!
Secondly, some patients who may already wear reading glasses, who are only slightly longsighted (perhaps without knowing it) and have previously enjoyed good comfortable distance vision, will find it harder to overcome this slight long-sightedness, and mid range (1-2 meters) and distance vision will start to blur. Suddenly needing two pairs of spectacles or varifocals is a common reason that patients attend for a free surgery assessment. So, for example – you may have managed without glasses in your 20's, but needed them in your 30's or 40's for reading. In your 40's onwards you start to notice that your distance vision is failing as well.
You can see if you have presbyopia by checking your optical prescription, if there is a number written in the "Add box" you will most likely have reached your mid-forties and require an extra power (an "addition") in the form of separate reading specs, bifocals or varifocals etc.
Eye treatments for Presbyopia
Although current laser refractive surgery techniques cannot completely cure true presbyopia, it may be able to restore your distance and mid-range focus. For true presbyopia a monovision treatment can be planned: This technique uses the non-dominant eye to focus at close range and the dominant eye is focussed for distance vision, in this way we can reduce your dependence on reading glasses dramatically. This technique is very well accepted and is a very popular laser treatment for the presbyopic patient.
Refractive lens exchange with a multifocal implant is another option that the older patient could consider. This treatment is generally a permanent fix. The refractive outcome is stable even in old age, and this treatment prevents the possible need for cataract surgery in later life. See the section on "intraocular lenses" above.
A basic understanding of the consequences of presbyopia is important for anyone considering refractive surgery.
Older people with low degrees of short-sightedness may avoid or delay the need for reading or close work glasses by removing their distance glasses when reading, but, successful refractive surgery for their short-sightedness will prevent this, so that close work glasses are then required. Many patients in this situation still prefer to be rid of the need for distance glasses, and will accept close work glasses, but it is something you should consider.
