How long does Laser Eye Surgery last?
This is a commonly asked question and quite understandable for those embarking on a procedure to correct their vision.
The answer to this question is for the vast majority Laser Eye Surgery is permanent with a definite reduction in dependency on glasses and contact lenses. Laser Eye Surgery produces a change in the power of the cornea, in a sense it carves out a permanent contact lens on the cornea. When performed with the correct technology in properly chosen cases and the cornea is mechanically strong, the power change will be stable for the long term and accounts for why Laser Eye Surgery is stable long term. However, for a small number, changes in vision can occur despite the cornea remaining the same.
To understand why changes in vision might occur after Laser Eye Surgery, it is useful to understand how light rays are focussed within the eye and how this is influenced by laser eye procedures like LASIK.
Light rays entering the eye must focus on the retina. This focus is accomplished by the cornea (67%) and the remainder by the lens within the eye. The focal power required for focusing depends on the length of the eye, which is calculated prior to surgery. After the age of 22 or so, the eye does not get any longer and the cornea hardly changes in overall power. Once the eye refraction (prescription) has stabilised it is unlikely that the power of the eye will change.
It is also important to note that the lens in the eye is dynamic, not just by the fact that it moves and changes shape inside the eye, but also because it gets new layers added on every year and becomes thicker, a bit like a tree trunk. As a result it then becomes harder which is why everyone finds it difficult to read in their 40s and need reading glasses – a condition called Presbyopia. The change in thickness and hardening of the lens within the eye can produce a change in power and in turn alter the focussing power of the eye. This often happens when a cataract is about to commence or well in progress. As a result of this change (varies in terms of age) the power of the eye changes, resulting in a need for a small spectacle correction.
Can Laser Eye Surgery be Repeated?
If you have undertaken Laser Eye Surgery previously, it can be repeated in the future. However, for those in their 50s and over will find that the lens inside the eye becomes more rigid over time, so we would usually recommend a more permanent solution such as Laser Lens Replacement . This procedure involves changing the dysfunctional lens and replacing it with a high performance multifocal (trifocal) lens.
This problem of the lens hardening cannot be prevented, although there are some who believe good living, consumption of antioxidants and other goodies can delay the onset and progress of lens hardening and cataract which in turn keep the eyes stable.
Laser Eye Surgery, in particular LASIK is a wonderful and liberating procedure for the vast majority of those seeking vision correction surgery. For the vast majority (selected well) the procedure is long lasting and for the small unlucky group who develop a change with advancing age, there are other options for lasting vision correction.
The key to a long-term successful outcome is to choose a great surgeon. At Centre for Sight, we have world-renowned surgeons that are involved with your care every step of the way. Supported by a team of highly trained technicians, our Surgeons provide high quality speciality vision correction and treatments to give our patients the best care.
Author Information
Authored by Sheraz Daya MD FACP FACS FRCS(Ed) FRCOphth, Consultant Ophthalmic Surgeon & Medical Director, June 2019.
Next review due February 2024.