It must be understood that the complications which may result from LASIK surgery are many. Some are a component of the risk undertaken in having the surgery performed, some result from inadequate screening, some result from an error by the surgeon and some from a malfunction of a device used in the surgery. It is, frequently, difficult to identify the causation, in part because the medical community is not always forthcoming in their assessment of post-surgical complications and, in part, because some complication can have multiple causation, some legally actionable and some not.  The first step in assessing any claim of malpractice is to determine the cause of the problem. This benefits the client even if it is determined that malpractice has not occurred as once causation has been accurately determined a treatment plan may become possible. 


LASIK surgery can possibly cause loss of vision or loss of best corrected vision. This can be due to infection or irregular scaring or other causes, and unless successfully controlled by antibiotics, steroids or other necessary treatment, could even cause loss of the infected eye. Vision loss can be due to the cornea healing irregularly which could add astigmatism and make wearing glasses or contract lenses necessary and useful vision could be lost. Glasses and contact lenses cannot correct many of the post-surgery complications experienced by post refractive patients. It is also possible that you may not be able to successfully wear contacts after LASIK.


Corneal Haze – Corneal haze results from the superficial cornea's healing reaction after contact with a laser. An eye care professional can assess the haze response of a patient's cornea under a slit lamp, but patients' experiences of haze vary. Corneal haze may not affect the patient's vision at all, but if severe, can cause loss of best corrected visual acuity. Corneal haze should not be confused with "hazy vision" that some patients may experience at night or in dim light

Decreased Night or Low-Light Vision - Characterized by symptoms such as glare, halos and starbursts that are seen around objects at night or in dim-light conditions. Although these symptoms do not necessarily interfere with visual acuity as it is measured by an eye chart, for some patients, the experience can significantly interfere with daily activities and driving at night.

Loss of Contrast Sensitivity - Refractive surgery techniques are designed to change the eye's focus and reduce or eliminate the need for glasses or contact lenses. However, there are other factors in the eye, which may affect vision quality, that are unrelated to eye focus. These factors can cause the quality of vision to vary greatly, even when a patient has 20/20 or better acuity. Contrast sensitivity measurement is the best method of quantifying the actual quality of a patients vision.

Immediately after LASIK refractive surgery, contrast sensitivity may be such that the patient's quality of vision is well below the normal range. After several weeks, or in some cases several months, the quality of vision and contrast sensitivity may recover to normal levels. For PRK refractive surgery, the amount of time required to recover to normal levels may be longer, up to six months. 

Severe Dry Eye - All patients should be aware that dry eye is a potential complication of LASIK. Additionally, patients who seek LASIK who have suffered from dry eye before, are bothered by contact lenses, are going through menopause or taking birth control pills should be certain to explore the increased potential for post surgical dry eyes with their doctor. Use of post-operative steroids after LASIK may exacerbate pre-existing dry eye. Previous contact lens wear may disrupt normal corneal physiology and cause ocular dryness. Hormonal changes during menopause or birth control pills can cause dry eye. 

Intraocular Pressure elevation - An increase in the intraocular pressure due to post-treatment medications. Usually resolved by drug therapy or discontinuation of post-treatment medications.

Over correction - Initially the eye is over-corrected since the cornea has a tendency to regress to its original state of refractive error. The regression may stabilize after 1-3 months. If you are permanently over-corrected, you may need glasses for reading and any close up work.

Under correction - In some, but not all cases, re-treatment may be considered. It must be understood that re-treatment is not always possible, is not always advisable as it can result in an even worse outcome and may not correct the problems being experienced.

Loss Of Best Corrected Vision - In this situation the patient is unable to see as well with glasses or conventional contact lenses after the surgery as he or she could see with glasses before the surgery. Sometimes specially designed contact lenses can be fit to help remedy this situation.

Double Vision - Two images appear when looking through one eye at a time. May also occur when both eyes do not align properly.

Glare - Headlight glare when driving at night. Glare is caused by light scatter which can occur with any loss of corneal transparency. 

Night (darkness) Myopia - This is a tendency for eyes to become more nearsighted in darkness,  leading to blurry vision. 

Halos and starbursts - This occurs when the pupil enlarges beyond the treated area at night or from surgically induced corneal distortion. Direct light sources (street lights, car headlights, etc.) become distorted in a variety of ways. 

Vision Blurring - This is when images appear blurrier after the refractive surgery than before.

Gray & Black Peri-operative Complications (occurring during the procedure)

Suture Use - May also be required which could induce astigmatism.

Reaction to Anesthesia or Medication - There are potential complications due to anesthesia and medications which may involve other parts of your body.

Microkeratome or Laser/computer malfunction - It is also possible that the microkeratome or the laser could malfunction making irregular cuts, damaging the stromal bed or forcing the procedure to be stopped before completion. The laser is controlled by a computer. Its malfunction during the operation will certainly impact upon your result.

Surgical error - While refractive surgery has become a highly automated procedure, it takes place at the hand of and under the supervision of a surgeon. His training and experience are factors which can impact significantly upon your outcome. Surgeons do make mistakes.

Gray & Black Post-operative Complications

Flap Melt - The flap begins to disintegrate and may require surgical intervention.

Flap Dislocation - This is a condition in which the corneal flap becomes dislodged and no longer properly aligns with the corneal bed. This is treated with surgical intervention.

Flap Wrinkles - A major or minor flap dislocation produces flap wrinkles. This is treated with surgical intervention.

Flap Striae - Fine folds noted in the flap are termed flap striae. There are various types of striae and treatment depends upon the type and the patient's symptoms. The treatment and cause of striae is currently somewhat controversial. If vision is threatened, then surgical intervention is indicated.

Central Island - This is a condition in which an island of corneal tissue remains in the visual axis following Excimer laser treatment. This is less common with the new generation of lasers that have been modified with programs to prevent this complication. This can cause undercorrection and visual blurring or distortion. Most central islands disappear spontaneously post-operatively without additional treatment.

Free Flap - Occurs when the microkeratome creates a flap without a hinge because the microkeratome blade fails to stop and cuts through the hinge. This is more likely to occur with the ACS type microkeratome and is quite uncommon. The flap will need to be replaced carefully, and reoriented to its original position after the laser treatment is completed.

Lost Flap - Could create serious healing and vision problems. Physical loss of the flap following an incident of a free or dislocated flap.

Incomplete Flap - Creation of an incomplete flap is usually due to a microkeratome malfunction. The procedure will usually need to be aborted and rescheduled at a later date.

Buttonhole Flap - Improperly produced flap where the top of the flap is removed causing a buttonhole like defect. Can cause subsequent healing and/or visual problems. 

Corneal Abrasion - A disturbance in the top layer of the cornea (epithelium) caused by the normal action of the microkeratome moving across the cornea. Some corneas are more susceptible to corneal abrasion.

Decentered Ablation - This complication is uncommon in the newer generation lasers. Corneal healing difficulties can produce a pseudo-decentered ablation especially with PRK. Usually caused by either poor patient fixation on the laser fixation light, poor patient head positioning, or poor centering of the laser beam by the surgeon.

Infection - This is probably the greatest risk in the first 24-72 hours after surgery. Antibiotic eye drops may be given to try to prevent this complication.

Post-treatment Discomfort - You may have some discomfort during the procedure, if any.. Patients having LASIK can expect some watering of the eyes the day of surgery, and some irritation for a day or two following the procedure. These symptoms are frequently controlled using eyedrops or oral pain medication.

Sands of the Sahara -  Diffuse lamellar keratitis (DLK) is a concentration of white blood cells on the surfaces of the corneal flap made before ablation by the laser. The cells accumulate in a tiny pattern, resembling sand dunes, that the microkeratome creates during the operation. It is essential that there be fast, aggressive treatment for Sands of Sahara. This condition may result from microscopic substances on the microkeratome blade, such as oil from the blade motor or tiny particles remaining from the blade manufacturing process (or resulting from improper sterilization), may be inflaming the corneal tissue. Another cause may be tiny bacterial toxins not always removed when blades are sterilized. It is also possible that debris in the tear film is to blame.


Other complications and conditions that can occur with LASIK surgery include: anisometropia (difference in power between the two eyes); aniseikonia (difference in image size between the two eyes); double vision; hazy vision, fluctuating vision during the day and from day to day; increased sensitivity to light which may be incapacitating for some time and may not completely go away. Some of these conditions may affect your ability to drive and judge distances and driving should only be done when you are certain your vision is adequate.

Gray & Black OTHER RISKS

Additional reported complications include: corneal ulcer formation; endothelial cell loss, epithelial healing defects; ptosis (droopy eye lid); corneal swelling, retinal detachments and hemorrhage. Complications could also arise requiring further corrective procedures including either a partial (lamellar) or full thickness corneal transplant using a donor cornea. Other complications include: loss of corneal disc, damage to the corneal disc, disc decentration and progressive corneal thinning (extasia).

Additional Risks if you are Considering the Following:

  • Monovision

Monovision is one clinical technique used to deal with the correction of presbyopia, the gradual loss of the ability of the eye to change focus for close-up tasks that progresses with age. The intent of monovision is for the presbyopic patient to use one eye for distance viewing and one eye for near viewing. This practice was first applied to fit contact lens wearers and more recently to LASIK and other refractive surgeries. With contact lenses, a presbyopic patient has one eye fit with a contact lens to correct distance vision, and the other eye fit with a contact lens to correct near vision. In the same way, with LASIK, a presbyopic patient has one eye operated on to correct the distance vision, and the other operated on to correct the near vision. In other words, the goal of the surgery is for one eye to have vision worse than 20/20, the commonly referred to goal for LASIK surgical correction of distance vision. Since one eye is corrected for distance viewing and the other eye is corrected for near viewing, the two eyes no longer work together. This results in poorer quality vision and a decrease in depth perception. These effects of monovision are most noticeable in low lighting conditions and when performing tasks requiring very sharp vision. Therefore, you may need to wear glasses or contact lenses to fully correct both eyes for distance or near when performing visually demanding tasks, such as driving at night, operating dangerous equipment, or performing occupational tasks requiring very sharp close vision (e.g., reading small print for long periods of time).

Many patients cannot get used to having one eye blurred at all times. Therefore, if you are considering monovision with LASIK, make sure you go through a trial period with contact lenses to see if you can tolerate monovision, before having the surgery performed on your eyes. Find out if you pass your state's driver's license requirements with monovision.

In addition, you should consider how much your presbyopia is expected to increase in the future. Ask your doctor when you should expect the results of your monovision surgery to no longer be enough for you to see near-by objects clearly without the aid of glasses or contacts, or when a second surgery might be required to further correct your near vision.

  • Bilateral Simultaneous Treatment

You may choose to have LASIK surgery on both eyes at the same time or to have surgery on one eye at a time. Although the convenience of having surgery on both eyes on the same day is attractive, this practice is riskier than having two separate surgeries. The second eye may have a higher risk of developing an inflammation if surgery is done on the same day than if surgery is performed on separate days. If a malfunction of the laser or microkeratome occurs causing a complication with the first eye, the second eye is more likely to also experience the same complication if the surgery is performed on the same day rather than on separate days.

If you decide to have one eye done at a time, you and your doctor will decide how long to wait before having surgery on the other eye. If both eyes are treated at the same time or before one eye has a chance to fully heal, you and your doctor do not have the advantage of being able to see how the first eye responds to surgery before the second eye is treated.

Another disadvantage to having surgery on both eyes at the same time is that the vision in both eyes may be blurred after surgery until the initial healing process is over, rather than being able to rely on clear vision in at least one eye at all times.


Regression - This is a situation where an improvement in vision was initially achieved and the cornea begins to return to its original shape. This may be corrected by an adjustment in the medication or, in a few circumstances, by an "enhancement" procedure. There is no guarantee that any negative result can be reversed by any re-treatment.

Diplopia - Distortion of vision not corrected by contact lenses or spectacles.

The complications listed here represent most of the presently known problems resulting from refractive (eye) laser surgery. Your surgeon should have warned you of these and any other known issues before your surgery. If you are thinking about surgery be certain your surgeon discusses all of these and any other known complications before your surgery and discusses those which may be unique to your circumstances in great detail. Several of these are avoidable by comprehensive pre-operative screening and proper device selection.