What prescription can Laser Eye Surgery correct?

When you go in for an eye exam at the opticians, the main thing you come out knowing is whether or not you need to wear glasses.

But they also might mention a bit about exactly why you need glasses. With your little prescription card in your hand, they’ll explain how you have shortsightednesslongsightednessastigmatism, or maybe a mixture of the above. Aside from that, there’s not much else you need to know.

But if you’re not too keen on a lifetime of glasses or contacts, then you’ll no doubt want to know if your prescription makes you suitable for other options like Laser Eye Surgery.

Does your eyeglass prescription qualify you for Laser Eye Surgery?

Your glasses prescription measures how much “refractive error” you have. A refractive error is when your eyes experience a problem focusing light accurately on the retina. The four most common types are: near-sightedness, far-sightedness, astigmatism, and presbyopia.


The level of refractive error is measured in diopters. Diopters are the metric used to indicate the strength of the lens. When you see numbers such as +4.00 (far-sightedness) or -2.00 (near-sightedness) on your prescription, they are diopters.

Typically, Laser Eye Surgery has the potential to treat up to +6.00 diopters of far-sightedness, 6.00 diopters of astigmatism, and -12.00 diopters of near-sightedness. However, the exact number depends on a variety of factors including the treatment type, eye health, technology available at the clinic, and the expertise of the surgeon.

Laser Eye Surgery has come a long way over the last few years, and so there are treatments today that can treat much higher prescriptions than were previously ever possible. This has created somewhat of a confusing market in which you can go to one clinic and be told there’s nothing they can do for you but go to another and be a candidate for treatment.

Before looking a bit more at such clinics that can treat very high prescriptions, let’s dive into some of the other factors that affect whether or not your prescription qualifies you for Laser Eye Surgery.

A stable prescription and good eye health

To have any type of Laser Eye Surgery, you should first have a stable prescription. This generally means your eyeglass prescription has not significantly changed for at least two consecutive years.

For this reason, there is a minimum age limit for Laser Eye Surgery of around 21 years.  LASIK is approved for those aged 18 and older, however, young adults are typically advised to postpone having the treatment until their mid-20s. There are, of course, exceptions to this rule.

Once you reach an age of “ocular maturity” your prescription typically stabilizes. There are certain conditions such as diabetes and other factors like being pregnant that can cause fluctuations in your prescription, but these are typically only temporary barriers to having treatment.

The quality of your vision

When you have the initial consultation with your ophthalmologist/specialist optometrist, they will assess the general quality of your vision. Here they will discuss anything that could influence your suitability.

Some of the symptoms that affect your vision and may influence your suitability for Laser Eye Surgery include:

  • Light distortion. Many people experience light distortion, including glare, halos, starbursts and ghosting/blurring around light sources, as part of their normal, everyday vision. However, it could be a sign of an underlying condition, and therefore may indicate it’s not the right time for you to have the treatment. On the flip side of this, it’s normal to experience some visual disturbances, particularly at night, as a part of the Laser Eye Surgery healing process.
  • Dry eye. Dry eye is a common eye condition that, due to changes in lifestyle and our increasing use of screens, affects more people year on year. Many people are living with dry eye syndrome without knowing it. Dry eye syndrome may affect your chances of being suitable for Laser Eye Surgery. On the other hand, Laser Eye Surgery can help people with dry eye secondary to contact lens wear.

The shape and thickness of your corneas

One of the measurements that can affect your suitability for Laser Eye Surgery is the shape and thickness of the cornea. For instance, as LASIK requires making a small flap in the outer layer of the cornea, there needs to be enough tissue to be reshaped in a way that helps focus light on the retina and achieve the desired amount of correction. If the cornea is too thin or misshapen, it may not be able to be reshaped to achieve the results you want.

The size of your pupils

If you haven’t gathered already, the initial assessment and consultation is a key part of the Laser Eye Surgery process. One of the most important tests is measuring your pupil size. For instance, if you have naturally large pupils, you may be at risk of increased side effects like poor night vision or blurry vision. Therefore, not everyone with large pupils is suitable for Laser Eye Surgery, but given the right tests and proper assessments, your treatment plan can be tailored accordingly to provide the best possible results.

Very high prescriptions

When Laser Eye Surgery was first introduced, specifically LASIK, it simply wasn’t an option for those with very high prescriptions.

Today though, thanks to advancements in technology, many people with higher prescriptions are candidates for the procedure. In fact, many people who’ve been told that they’re unsuitable for LASIK in the past may find that today they can have it no problem.

Of course, your exact chances of being suitable is determined on a case by case basis. The best way to find out if LASIK — or more likely ReLEx SMILE — is suitable for you is to speak with a highly-qualified surgeon.

Given the right expertise and equipment, they’ll be able to assess your vision and tell you if Laser Eye Surgery is safe and can help you.

Find out if your prescription makes you a suitable candidate for Laser Eye Surgery by leaving us a comment below or getting in touch with our friendly team of eye experts.