Doctor's Answers (4)
Presbyopia refers to the loss of autofocusing capability of the eye. This happens because the natural crystalline lens of the eye becomes larger and stiffer with age, and there is no way currently to reverse the process.
LASIK also does not restore the flexibility of the lens, and therefore does not reverse presbyopia.
When you are presbyopic, your eye focuses mainly for one distance without glasses:
Either far, or near, but not both.
An eye with 'zero' spectacle power would see far clearly without glasses, but not near.
An eye with some short-sighted/myopic spectacle power would see near clearly without glasses, but not far.
The most predictable way to reduce the need for glasses would therefore be 'monovision', whereby one eye sees well in the distance, and the other sees well for near, without glasses. This is a compromise and can take some time to get used to, but generally speaking, as long as the difference in spectacle power between eyes is not too great, many people find monovision to be a very useful situation to have.
So the most that LASIK can do to help your presbyopic situation is to give you monovision, ie to make one eye as near to zero spectacle power as possible, and to make the other eye slightly myopic so that it can see near without reading glasses. If this is a situation which you would like to have, then LASIK can be considered. Otherwise, it might be best to continue with your current situation and to wear glasses as the need arises, whether for far or for near, or both.
Do understand that presbyopia occurs as a result of age-related changes in the lens of the eye.
LASIK or any forms of laser vision correction (LVC) makes its effect felt by way of changes on the surface of the eye, namely the cornea. Hence, LVC cannot spare patients from the inevitable effects of presbyopia that effects everyone in their middle ages.
It is possible though to correct your residual myopia and astigmatism. This would allow you to have good unaided vision at far distances but you would still need to rely on reading glasses for the close distance.
In some cases, the surgeon may leave one eye slightly myopic to enable you to read through that eye without glasses. This is called monovision. Discuss this with your surgeon and he may offer you a trial of monovision with the use of contact lens.
Presbyopia occurs naturally as people who are around 40 years old, as the natural lens harden and muscle fibres becomes less flexible. As a result, you may feel that it is increasingly difficult to look at objects close to you.
Even if you have undergone LASIK before, it may still be possible for you to opt for presbyopia correction to reduce your dependency on glasses. However, the suitability for the correction would greatly depend on the remaining cornea thickness that you have left.
The most common strategy for presbyopia correction is the Monovision treatment, also known as the "Blended Vision treatment". In this case, your dominant eye will be corrected to see clearly for distance (objects far away from you), and your other, the non-dominant eye, will be corrected to see better for near vision (objects near to you). If the difference in both eyes' refractive powers are kept to 150 degrees or less, the "Blended Vision phenomenon" will occur as both eyes will complement each other to see both far & near at the same time.
If you would like to opt for presbyopia correction, you would have to bear in mind that presbyopia is a progressively dynamic condition, and that there are no treatments that can treat or cure the condition as of now. What doctors can offer are compromised solutions to the presbyopia problem to help you reduce your dependency on your glasses.
Some patients are eligible for, and do choose the option of an enhancement procedure after previous Lasik. You should discuss this with your Ophthalmologist after a detailed clinical examination.
However, you should consider that a small degree of residual myopia is actually useful for a person in your circumstance as it helps you with your near vision. In fact for patients who are presbyopic and considering Lasik, we commonly intentionally leave them under corrected in the non-dominant eye, in order to give them functional near / distance vision in both eyes (a technique called mono-vision).
Again, you should consider your specific situation with your attending Ophthalmologist. Best of luck!