Laser eye surgery is an increasingly popular way for Canadians to correct their vision, but what can it do for you? Many people have specific questions about LASIK, which has been a leading method for laser eye surgery for over 30 years.
Our practice is here to tell you everything you need to know about LASIK, including the risks. Read on and learn all about this procedure so that you can decide whether it will be right for you.
What is LASIK?
LASIK removes tissue from the cornea with an ultraviolet laser (also known as an excimer laser). Changing the corneas shape affects the way that it focuses light onto the retina, which can correct several refractive issues.
LASIK is a quick procedure that can usually be completed in 10 to 15 minutes.
Why Do People Get LASIK?
Most people get LASIK to correct one of three common refractive errors: myopia, hyperopia, and astigmatism.
Myopia
Myopia is commonly called nearsightedness. It occurs when the eyeball is abnormally long or when the cornea curves too abruptly. Either of these factors can cause light to focus in front of your retina instead of directly on top of it. As a result, a person with myopia will experience blurry vision when trying to focus on faraway objects.
One study predicts that nearly 5 billion people will have myopia by the year 2050. LASIK represents an effective way to correct myopia without the need for glasses or contacts.
Hyperopia
Hyperopia, or farsightedness, is the opposite of myopia. People with hyperopia have problems focusing on objects that are short distances away or right in front of them. Hyperopia occurs when the eye is not long enough, or when the lens focuses light behind the retina.
Data from the National Eye Institute in the US suggests that nearly 10% of the population is noticeably affected by hyperopia, although many more people likely experience it in a mild form. LASIK can be a worthwhile procedure for people whose hyperopia affects their ability to read, work, or perform other important tasks.

Astigmatism
Astigmatism occurs when the curves in the lens or cornea are uneven. It can appear at birth, but may also develop at any time during a persons lifetime.
Genetics can be a risk factor for astigmatism, but it can also affect people without a strong family history of the condition. Astigmatism often occurs with myopia or hyperopia, and can cause blurry vision when focusing at any distance. LASIK can alter the shape of the cornea to correct astigmatism.
Is LASIK Safe?
All forms of laser eye surgery come with some degree of risk. Many people worry that LASIK can result in vision loss, but this is statistically one of the least likely complications. LASIK currently has a success rate of more than 96%, and serious complications only occur in 0.3% of cases.
The most common risks associated with LASIK still appear in less than 4% of cases. They include:
- A temporary reduction of tear production, which may cause dry eyes up to six months after the procedure.
- Increased light sensitivity at night, which may come with double vision, halos, and glare for several weeks.
- Undercorrections or overcorrections, which can require additional LASIK surgery. In rare instances, LASIK can also create astigmatism where it was not previously present.
- Infection, which may in turn cause tear overproduction.
- Vision that slowly regresses to the way it was before LASIK, although this is also one of the least likely side effects.
It is also worth noting that more than 90% of patients who undergo LASIK end up with 20/20 visionor better. Due to the potential benefits and relatively low risks, LASIK is generally viewed as a reliable way to correct refractive problems.
When Not to Get LASIK
Since LASIK uses a laser to create a flap in the cornea, it is not a suitable fix for every condition. People with the following conditions may want to consider alternative procedures:
- Thin corneas: people whose corneas are too thin for LASIK may benefit from PRK instead. This is a different type of laser eye surgery that reshapes the cornea bed instead of creating a flap the way LASIK does. PRK can also be used to correct myopia, hyperopia, and astigmatism.
- Presbyopia: presbyopia is a condition that makes people less able to focus on nearby objects as they age. Unlike hyperopia, it occurs when the lens of the eye becomes less flexible over time.
LASIK cant correct presbyopia. If you have presbyopia, you may be a candidate for refractive lens exchange (or RLE), which involves surgically replacing the eyes lens with a prescription lens implant.
LASIK is also not recommended for people who:
- Are under 18, since their vision may still be changing
- Pregnant or nursing women, since their hormone levels can change and alter their prescription
- Take prescription drugs, which can affect LASIK results
- Do not have a stable prescription
- Have autoimmune diseases, which can prevent proper healing after the procedure
- Have dry eyes, which can be made worse by LASIK
- Have pupils that dilate too much in the dark, since this can can cause unwanted glare or halos after the procedure
- Have excessively steep corneas
Ask Your Eye Doctor if LASIK Can Benefit You
Your optometrist or ophthalmologist is the most qualified person to recommend LASIK surgery. Be sure to consult them if you are thinking about having this procedure, and make sure to follow their recommendations.