How Does Lasik Work?

How does lasik work to improve your eyesight? By restoring your vision to almost 100%! Laser-assisted in situ keratomileusis—also known as LASIK—works as a remedy for vision problems. It may not restore perfect vision, but it is still a better alternative to glasses or contact lenses. Lasik was approved by the FDA about 20 years ago as a cure for specific vision problems. In this comprehensive guide, you will learn how Lasik surgery works to improve your vision. 

how does lasik work
How Does Lasik Work: Evaluation

Lasik: How Does It Work

In eyes with good vision, the cornea, which is a dome-shaped clear tissue located at the front of your eyes, refracts (bends) light precisely onto the retina at the back of the eyes. However, when the cornea doesn’t refract correctly because of certain eye problems, it results in blurred vision.

Lasik works by reshaping the cornea with a special type of laser, which is used to precisely shape the cornea to provide the necessary refraction to improve your vision.

While glasses or contact lenses can correct vision problems, they cannot improve vision like Lasik does at the organ level.

Why Is Lasik Done & Possible Risks

Lasik surgery is performed to correct the refractive errors of any one of these vision problems:

Nearsightedness (myopia) 

It is when you can see objects that are fairly close clearly, but those that are far away are blurry. Myopia occurs when your eyeballs are slightly longer than normal or when the cornea curves so sharply that light rays focus in front of the retina, thereby blurring distant vision.

Farsightedness (hyperopia)

Occurs when near vision, and sometimes even distant vision become blurry. Hyperopia occurs when your eyeballs are shorter than normal or when the cornea is so flat that light focuses behind the retina instead of on it.


Is the disruption of your near and distant visions. Astigmatism occurs when the cornea curves or flattens unevenly that light can’t properly focus on your retina.

Loss of vision is very rare. Nevertheless, certain side effects occur after getting Lasik eye surgery. These side effects are common but are usually cleared up after a few weeks or months, and they include, dry eyes and temporary visual problems; i.e. glare, undercorrection, overcorrection, flap problems, and maybe even regression back toward your original prescription. 

Conditions That Increase Risks

Certain health conditions can increase the risks associated with Lasik surgery. If you have any of these conditions, your ophthalmologist may not recommend getting Lasik:

  1. Autoimmune disorders, such as rheumatoid arthritis;
  2. A weakened immune system caused by HIV or immunosuppressive medications;
  3. Constant dry eyes;
  4. Recent changes in vision due to pregnancy, breast-feeding, hormonal changes, medications, or aging;
  5. Inflammation of the cornea; 
  6. Lid disorders, eye injuries or diseases, such as uveitis, herpes simplex affecting the eye area, glaucoma, or cataracts;
  7. Suffering from, or having a family history of eye disease that causes the cornea to thin and bulge; or
  8. Participating in contact sports where there is an increased risk of getting blows to the face.
lasik how does it work
Lasik How Does It Work Pre-Op Tests

How Does Lasik Eye Surgery Work

In this segment, we will cover four components: How you can prepare for the surgery, what you need to expect before the procedure, how the procedure itself works, and what happens post-op.

How to Prepare

Here’s what you need to do to prepare for the surgery:

Learn the Cost of Surgery

Lasik surgery is typically considered an elective procedure, so most insurance companies won’t cover the cost of the surgery and treatment. Read how affordable Lasik is to learn more.

Have Someone Drive You Home

You will not be allowed to drive after the surgery due to blurry vision. Therefore, arrange for a family member or a friend to drive you home. 

Avoid Putting Makeup & Other Cosmetics

Don’t use makeup, lotion or cream, or perfume 24 hours before the surgery. Your opthalmologist may also instruct you to clean your eyelashes in the days leading up to the surgery to remove debris and minimize the risk of you getting an infection. 

What To Expect Pre-Op

Your ophthalmologist will conduct an evaluation to determine if you’re a good candidate..

If you wear contact lenses, you will need to stop wearing them and switch to glasses because contacts can change the shape of your cornea. So, avoid wearing contacts for at least a few weeks before your evaluation and surgery. 

Depending on the type, here’s how long you need to stop wearing contacts:

  • Hard lenses—Four weeks.
  • Soft lenses—Two weeks.
  • Toric soft lenses or rigid gas permeable lenses—Three weeks.

During the evaluation, your ophthalmologist asks about your medical and surgical history. They give you a comprehensive eye examination to evaluate your vision, as well as to assess whether you can undergo the procedure safely. Specifically, they will be looking for signs of the following during the evaluation:

  • Eye infection
  • Eye Inflammation or inflammation of the cornea
  • Dry Eyes
  • Large Pupils
  • High eye pressure

Your ophthalmologist will also measure the cornea (shape, thickness, and irregularities) to determine which areas need reshaping and the precise amount of tissue that needs to be removed.

Furthermore, your ophthalmologist will discuss the risks associated with Lasik surgery, what you need to expect pre and post-op, and how the procedure works. They will remind you that Lasik doesn’t restore vision to 100 percent as you might still need to wear glasses or contact lenses for certain activities, such as reading and driving. 

How Does Lasik Surgery Work

Lasik surgery works by utilizing the bladeless technique. You might wonder ‘how does bladeless lasik work?’ and the simplest explanation is that the bladeless technique relies on infrared laser to create a microscopically thin flap, instead of having to cut up a flap by hand. The laser is also used to reshape your cornea. The procedure might feel uncomfortable, but Lasik is proven to be a safe procedure and very few people have any long-term side effects.

As for the surgery itself, here’s how it works:

  1. Your eyes are open during the entire procedure. Your ophthalmologist will numb your eyes with eye drops. While you might feel pressure—like a finger pressing against your eyelid—you won’t feel pain.
  2. Your ophthalmologist will place an eyelid holder on your eye to keep you from blinking, and a suction ring to keep your eye from moving. You will experience dim vision, or it may go completely black.
  3. Your ophthalmologist will create a thin flap in your cornea using a laser programmed with your eye measurements. 
  4. Next, your ophthalmologist will lift and fold your flap back to reshape your cornea so that it refracts light better. They can reshape your cornea by instructing you to stare at a light shining in your eye to keep your eyes from moving. 
  5. Finally, your ophthalmologist will fold the flap of tissue back down and it will start to settle into place within two or three minutes, healing quickly.

What To Expect Post-Op

You might experience the following:

  • Itching or burning
  • Feeling as if there’s something in your eyes
  • Blurry or hazy vision, glare, starbursts, or haloes around lights
  • Sensitivity to light
  • Dry eyes

For dryness, your ophthalmologist might give you some eye drops as well as antibiotics and steroidal eye drops. Additionally, your ophthalmologist might have you wear a shield over your eyes to stop you from touching them, especially while you’re asleep.

Your ophthalmologist will ask you to return one day after your surgery to get your vision tested and make sure that your eyes are healing.

Lasik Surgery: Next Steps

Getting Lasik is a relatively safe and uncomplicated procedure if you want one. We advise you to consult with your doctor and learn about the cost and benefits of the procedure before you go through with it.


[1] About Lasik Eye Surgery. “LASIK eye surgery.” Mayo Clinic.

[2] How Lasik Eye Surgery Works. “LASIK Eye Surgery: How It Works.” WebMD, 2020.

[3] Everything You Need to Know About Lasik. “How Does LASIK Work? Everything You Need to Know.” RSC, 2022.

[4] Lasik Eye Technology. “How does LASIK work? LASIK Eye Surgery Technologies Explained.” Assil Gaur Eye Institute of Los Angeles, 2022.

[5] Comprehensive Guide for Lasik Surgery. “LASIK Eye Surgery.” Cleveland Clinic.