Laser-assisted in situ keratomileuses (LASIK) surgery is a procedure that reshapes corneal tissues with lasers. For most people, LASIK can offer permanent vision correction, but cannot change certain factors that undermine vision or eye health. While some of these factors, like age, are non-modifiable, others may be. People who undergo the procedure can still experience vision deterioration later in life. So it is important to continue to get regular eye exams after having LASIK surgery, even if vision is good.

What Is LASIK Surgery?

LASIK surgery permanently changes the shape of the cornea (the clear covering of the front of the eye). Lasers used during the procedure can include a femtosecond laser to create the corneal flap and an excimer ultraviolet laser to reshape the corneal tissue. A microkeratome blade is used to make the flap in most cases.

Pulses from the laser vaporize and reshape a portion of the cornea. After the procedure is completed, the flap is replaced on the cornea (corneal repositioning) without the need for stitches.

The conditions that LASIK treats include:

  • Myopia (nearsightedness): When the eye is longer than the normal eye, the light rays focus at a point in front of the retina, resulting in a blurry view of distant objects. One in four people in the United States has some degree of myopia
  • Hyperopia (farsightedness): The eye is shorter than normal and light rays are aimed at a focus point behind the retina, causing a blurring of objects viewed up close.
  • Astigmatism: An uneven curvature of the cornea causes a distortion of images. Objects at all distances can appear blurred, especially after dark with bright lights

Who Should Not Get LASIK?

Not everyone will achieve 20/20 vision with LASIK, and some may even experience unsatisfactory results.

LASIK is not recommended if you:

  • Have a corneal dystrophy like keratoconus
  • Have a lazy eye or amblyopia
  • Wear glasses or a contact lens prescription that has changed in the past year
  • Already have thin corneas
  • Are younger than 18 years old
  • Have fluctuating hormones
  • Are pregnant or breastfeeding
  • Are taking medications that cause vision changes
  • Are active in contact sports
  • Have blepharitis (inflammation of the eyelids with crusting of eyelashes)
  • Have large pupils
  • Had previous refractive surgery
  • Have dry eyes

People with certain medical conditions or who take certain medications should refrain from having LASIK because of possible trouble with healing.

Possible contraindications include:

  • Taking medication for a disease that affects wound healing (such as autoimmune diseases, and rheumatoid arthritis)
  • Immunodeficiency states such as an HIV infection
  • Diabetes
  • Taking retinoic acid or steroids

Discuss with your healthcare provider if you have a history of any of the following:

  • Herpes simplex or herpes zoster (shingles) involving the eye area
  • Glaucoma, a disease in which damage to the optic nerve leads to progressive, irreversible vision loss
  • Ocular hypertension, when the pressure in your eyes is above the normal range, with no detectable changes in vision or damage to the eye structure
  • Eye diseases or inflammation
  • Eye injuries or previous eye surgeries

What to Expect After LASIK

While most people will experience an immediate improvement in vision after surgery, it could take two to three months for the cornea to fully heal.

During that time, you should refrain from:

  • SwimmingHot tubs or whirlpoolsContact sportsDriving at night (if you experience halos, glare, or difficulty seeing at night)Using creams, lotions, makeup, or perfumes (while a one-to-two week wait is customary before you can start applying makeup, ask your healthcare provider when it is safe to start using these again)

Reasons for LASIK Failure

Some of the common complications of Lasik surgery are:

How Effective Is LASIK Surgery?

A 2016 study that assessed vision-related quality-of-life outcomes and satisfaction five years after LASIK surgery noted that 91% of patients were satisfied with their vision and 94.9% did not wear distance correction. Less than 2% of patients noticed visual phenomena (halos and glares around bright lights), even with spectacle correction.

  • Dry eye syndrome
  • Light sensitivity
  • Problem with night vision, such as halos and glares
  • Vision distortion, including blurring and diplopia (double vision)
  • A scratchy feeling in the eye
  • Astigmatism

The Patient-Reported Outcomes with LASIK (PROWL) Study noted that approximately 5% of patients have some type of complication after surgery. Some of the effects can subside on their own during healing, and others may become permanent if too much or too little corneal tissue is removed or if it is irregularly removed.

Complications can also arise from infections or dislocation of the corneal flap.

The study also showed that less than 1% of study participants experienced “a lot of difficulty” with or inability to do usual activities without corrective lenses because of a visual symptom (starbursts, ghosting, halos, glare) after LASIK surgery.

Changes In Vision After LASIK

Although LASIK is generally an effective and usually safe way to correct vision problems for most people, other conditions and aging can affect vision and eye health. These are not related to LASIK surgery.

The Importance of Proper Wound Care

For the best results after surgery, follow wound care instructions carefully. It is important to maintain your after-surgery schedule of eye drops, usually a combination of antibiotic and steroids for two weeks, in addition to preservative-free artificial tears for a minimum of one month, or whatever your healthcare provider directs. Smoking can also contribute to dry eye syndrome.

Here are some conditions to watch for:

  • Cataracts: This condition occurs in about half of people ages 65 to 74 and in 70% of those ages 75 and over, causing symptoms like blurriness, poor night vision, or distorted colors. LASIK does not prevent or slow cataract development. If you need surgery to correct cataracts after earlier LASIK surgery, it may be a bit more difficult to choose the proper implant lenses, but it can be accomplished.
  • Glaucoma: Ophthalmologists screen for glaucoma by checking intraocular pressure and looking for optic nerve damage. LASIK surgery thins the cornea, leaving it softer and more flexible, so glaucoma screenings after the procedure may show lower intraocular pressure readings and make it trickier to diagnose early glaucoma. If you have any stage of glaucoma, discuss all of the possible issues with your healthcare provider.
  • Progression of other conditions: LASIK will not prevent other eye-related aging issues, such as myopia, hyperopia, or astigmatism. In fact, the presence of some of these conditions may create a need for a second surgery or treatment some years after the first LASIK surgery.
  • Retinal detachment: If you have high myopia, the risk of retinal detachment, holes, or tears remains unchanged after LASIK. Surgery does not reduce the risk because the back structures of the eye remain the same.
  • Dry eye syndrome: As your eyes produce fewer tears due to aging, you may feel itching, burning, or scratching in the eyes. Since dry eyes sometimes are a side effect of LASIK, this may make your problem feel worse. Ask your healthcare provider if you can have your tear production measured before you decide whether to have LASIK. If your tear levels are already low, you are more likely to develop chronic dry eye afterward.

LASIK Retreatment

While LASIK has highly positive outcomes, some people are likely to need retreatment or additional surgery.

A 2017 study in BioMed International suggests that approximately 75% of people who undergo LASIK surgery will maintain vision correction for at least 2 years, and possibly permanently. However, 10% will experience age-related vision problems. In such cases, retreatment may be needed. One study in the Taiwan Journal of Ophthalmology suggests that as many as 35% of people who undergo LASIK may need additional surgery when their vision starts to fail.

More than 10% of LASIK patients in the United States require a second surgery called retreatment to restore the desired vision correction.

This is more likely for people who:

  • Were extremely nearsighted or farsightedHad higher astigmatism of over 1 diopter (D), before LASIK. A diopter is a unit used to measure the correction, or focusing power, of the lens required for your prescription.Had LASIK at an older age, specifically over the age of 40

What You Can Do

While some factors that affect vision cannot be changed, we can keep our eyes healthy in many ways.

  • Sunglasses: Use sunglasses that block out 99 to 100% of both UVA and UVB radiation to lower your risk of eye damage, cataracts, and age-related macular degeneration.
  • Eye strain: Avoid staring at laptops or electronics for long periods of time. Try the 20-20-20 rule: Every 20 minutes, look away about 20 feet in front of you for 20 seconds.
  • Lubricating eye drops: Also called artificial tears, these drops add moisture to the eyes and relieve discomfort. Eye drops marketed for relieving red-eye contain ingredients that can make your dry eye symptoms worse over time.
  • Diabetes: Maintaining a healthy weight can decrease your risk of developing diabetic retinopathy or glaucoma.
  • Smoking: This habit increases the risk of developing age-related eye diseases, such as maculardegeneration and cataracts, and can damage the optic nerve.
  • Medications: Tell your ophthalmologist about medications you take since certain ones (like those that treat osteoporosis) can affect eye health.
  • Family medical history awareness: Since some eye diseases are inherited, find out whether anyone in your family has an eye-related disease to determine your potential risks.
  • Wear protective eyewear: Protect your eyes when playing certain sports, working in jobs that can result in eye injuries, and doing DIY projects.
  • Eat a healthy, balanced diet: That includes plenty of deep yellow and green leafy vegetables and fruits. Eating fish high in omega-3 fatty acids, such as salmon, tuna, and halibut can also provide good eye nutrition.
  • Age-Related Eye Disease Study (AREDS2) vitamins: Daily vitamins can help slow the progression of macular degeneration. Taking nutritional supplements every day may help lower the risk of developing late-stage or wet age-related macular degeneration.

Remember to get regular eye exams to spot any early changes in vision when they are most treatable.