If you’re one of the many bespectacled people who have considered LASIK laser eye surgery, you may have heard of the term “eligibility criteria” or something similar. Basically, are you suitable for LASIK?

While the definitive answer to this question lies with your eye specialist, there are some general guidelines that can help you know whether to expect a resounding “yes, you are!” or a disappointing “no, unfortunately not.”

General factors that determine your suitability for LASIK eye surgery include:

• Your prescription. This is a rather loose guide as it goes hand-in-hand with the corneal thickness (which we’ll talk about next). As a rule of thumb, LASIK can correct prescriptions up to around -11 diopters of near-sightedness, +5 diopters of far-sightedness, and up to -5 diopters of astigmatism. Another important aspect of your prescription is that it has proven to be stable for at least the past year or two. What a shame it would be to have spent thousands of dollars on laser eye surgery only for your script to change!
• Your corneal thicknesses. LASIK is built on the idea of vaporizing selected areas of your cornea to change its shape in such a way that alters the way light passes through this tissue. It then stands to reason that if you don’t have a lot of cornea to vaporize then, well, LASIK may not be a great idea for you. The higher your prescription, the more corneal tissue will need to be removed.
• You don’t have any other vision-limiting conditions. LASIK and any other refractive surgery techniques are able to correct your prescription to provide clear, spectacle-free vision. However, they can’t improve any vision that’s been lost from an eye disease, such as macular degeneration or a lazy eye.

Beyond these, there are some other common situations that the aforementioned bespectacled people may find themselves in as they figure out whether LASIK is for them.

 

Can I Have LASIK If I’m pregnant?

If you’ve ever experienced pregnancy or are close to some who has, you’ll know there’s quite an extensive list of things a pregnant woman can’t have or do. For example – soft cheese, alcohol, unwashed salads, rollercoaster rides, contact sports, cigarettes, sleeping on her back… the list goes on. Do we add LASIK eye surgery to the list?

The general recommendation is that a pregnant woman delay laser eye surgery until a few months after the birth. The reason for this is because hormonal changes can cause the eye’s prescription to fluctuate during pregnancy as well as slow the healing response of the body. Some medications used during the procedure and post-operative period may be harmful to the baby, either as its developing in the womb or during breastfeeding.

However, as with many recommendations, there are exceptions. Some eye specialists may agree to perform LASIK on a pregnant woman under certain conditions, such as if she is able to undergo the procedure without a sedative, or if she has a particularly good reason for needing LASIK at the moment.

 

Can I Have LASIK If I have astigmatism?

There should have been a spoiler alert before discussing the general factors for LASIK eligibility above. If you read it all, you’ll know the answer to this question is yes.

Astigmatism is an irregularity of either the cornea (most commonly) or the lens inside the eye (less commonly). This results in a distortion of your vision that can be usually fully corrected with glasses or contact lenses. Historically, laser eye surgery was unable to correct for astigmatism, which is why many people still think they are unsuitable. However, nowadays, various laser eye surgery methods, including LASIK, are able to correct up to moderate levels of astigmatism. In addition to meeting the prescription limits, you must also fulfil all the other eligibility criteria, such as having a stable script and sufficient corneal thicknesses.

 

Can I Have LASIK If I have dry eyes?

We’ve all experienced a dry eye (or two) at some point in our lives. The real question is, how dry is too dry? Dry eyes is now recognized as a real eye disease, not simply a side effect of a bad night’s sleep or staring at the computer for too long.

LASIK and other types of laser eye surgeries are known to exacerbate or cause dry eyes. This common side effect can last for months and is thought to be a result of disruption to the corneal nerves during the procedure, which affects tear production. In addition to being uncomfortable, or in some cases, downright painful, dry eyes can negatively affect your vision after surgery. Although no one is immune to dry eyes, certain factors can make you more at risk of experiencing dryness after LASIK surgery. These include being of the female gender, menopause, an autoimmune disease called Sjogren’s syndrome, and pre-existing dry eye.

Having symptomatic dry eyes doesn’t immediately rule you out from having LASIK. However, in consultation with your eye specialist, you may want to consider whether LASIK is the best option for you. Other techniques such as PRK (photorefractive keratectomy) or SMILE (small incision lenticule extraction) are associated with a lower risk of post-operative dry eye and may be better solutions for people with dry eye disease.

 

Can I Have LASIK If I have floaters?

Floaters are little specks, squiggles, or lines that drift across your vision. When they first appear, often people think they’re seeing a pesky fly or just caught a glimpse of a mouse running under the table. In fact, floaters are usually a natural part of aging. They occur as the vitreous gel inside the eye liquifies, which results in little fragments of debris that float about inside the eyeball. We see these fragments as floaters. While they can be annoying, age-related floaters are entirely harmless.

Having floaters does not exclude you from undergoing LASIK eye surgery but be aware that having LASIK won’t get rid of them. Some patients are also interested to know whether having LASIK will worsen their existing floaters. The answer to this is no – however, some people may become more aware of those pesky squiggles simply because they’re paying more attention to their newfound clear vision.

As a side note, some floaters are not a natural part of aging and may be a symptom of a sight-threatening condition, such as a retinal detachment. Never ignore the sudden appearance of floaters; see your eyecare professional immediately.

 

Can I Have LASIK If I have cataracts?

Well, no one’s saying you can’t have LASIK if you have cataracts. But it would be a bad idea. Cataracts are a progressive opacity of the lens inside your eye, typically resulting from aging. In addition to causing your spectacle prescription to shift as the cataract grows, the presence of a cataract limits your vision by literally blocking light from entering the eye, something for which LASIK would offer no benefit. If you cast your mind back to those general eligibility criteria, that’s already two black marks.

If you have cataracts that are affecting your vision, your eye specialist may instead recommend (surprise!) cataract surgery. The benefit of cataract surgery is two-fold. First, your cataracts are removed, and suddenly your eye can be flooded with bright, vibrant light. Second, a cataract procedure includes implanting an artificial lens, called an intraocular lens. This implant is typically calculated to correct for your spectacle prescription – yes, astigmatism and all. The added advantage of cataract surgery as a vision correction method is that it doesn’t rely on you having a stable script nor a minimum corneal thickness. In fact, cataract surgery doesn’t even rely on you having cataracts. A refractive surgery technique known as clear lens exchange, or refractive lens exchange, is essentially a cataract surgery procedure minus the cataracts.

 

Can I Have LASIK If I have diabetes?

Having diabetes will not exclude you from having LASIK; however, your eye specialist will want to see your blood sugar levels under good control. There are two reasons for this. One is that elevated sugar levels can cause your prescription (and vision) to fluctuate due to changes in the water content of your eye’s lens. The other reason is that poorly controlled blood sugar levels can impact your body’s ability to heal. This results in an increased risk of an eye infection after laser eye surgery and potentially poorer visual outcomes.

Some people with long-term, poorly controlled diabetes may have diabetic retinopathy, a complication of diabetes affecting the retina of the eye. Severe stages of diabetic retinopathy can result in permanent vision loss. If you choose to undergo LASIK (now that your blood sugars are nicely managed), be aware that laser eye surgery will not restore any vision lost from diabetic retinopathy.

 

This is not an extensive list of every situation that needs consideration before undertaking LASIK eye surgery. There are other reasons that you may not be eligible for LASIK. Your eye specialist or local optometrist will be the best people with whom to discuss your individual circumstances and expectations.