Doctor performing surgery

LASIK is the most popular and successful method of laser eye surgery. The all-laser LASIK technique, performed at our state-of-the-art laser center in New Jersey, is our preferred laser vision correction treatment in patients with nearsightedness, farsightedness, or astigmatism.

Our doctors have been performing LASIK for over 25 years and has treated thousands of extremely satisfied patients.

In fact, Dr. Hersh was the lead author of the clinical trial that led to the first FDA approval of the excimer laser for vision correction surgery in 1995 (click the title below), so his practice has some of the longest and most extensive experience in LASIK in the U.S.

Our doctors perform LASIK, PRK, and other types of refractive surgery.

The Optical Principle of LASIK:

tissue contact lens diagram

LASIK works like a contact lens. However, instead of putting a contact on your eye, the laser removes a thin film of tissue from the surface of the cornea (the clear, front “watch crystal” of the eye).

So, rather than putting on a contact lens, in LASIK we are removing what can be thought of as a tissue contact lens. Just like a contact lens, this focuses your vision to give you clear sight.

How is LASIK Done:

In LASIK, a pancake-like thin flap of the cornea is first prepared with a high-speed laser called Intralase. Here at the Cornea and Laser Eye Institute – Hersh Vision Group in New Jersey, we use the all-laser technique exclusively, whereas older technology involved using an actual blade to create the flap.

The LASIK flap acts to preserve the surface epithelial cells (which are like tiles on a floor) to promote quick healing and improvement in vision. Visual recovery is typically overnight (in fact, most patients can drive and return to work the day after LASIK).

Next, the Wavelight excimer laser, using a beam of invisible ultraviolet light energy, is used to remove a small amount of tissue from the corneal surface beneath the flap.

The actual laser application takes approximately 1 minute. During the procedure, an eye-tracking mechanism makes sure that all laser spots are placed in the proper location, even if your eye inadvertently moves.

The specifications of the laser application are determined by the computer of the laser which is pre-programmed with your individualized data as determined during our measurements examination. In the topography-guided Contoura technique, your actual corneal map is also programmed directly into the laser.

After corneal reshaping, the LASIK procedure is finished when the corneal flap is repositioned. When the flap is replaced, it lies in the bed of the laser-removed tissue, causing the surface to change shape. This provides the effect of decreasing nearsightedness, farsightedness, or astigmatism.

The LASIK Procedure:

Lasik procedure diagram

LASIK procedures are performed here at CLEI in our laser suites. The entire process takes approximately 3 hours. During the first hour, we take more tests to confirm our previous measurements.

The procedure is performed in two steps and is entirely comfortable. You will be given an eye drop anesthetic to numb the eye and also a mild sedative to relax you.

In the first step to create the LASIK flap, a lid retainer supports your lids to avoid blinking during the procedure. You will be looking up at a microscope light and the actual laser treatment will take around 1 minute. After a short break, the Wavelight laser will be used to reshape the cornea.

Your surgeon will move the LASIK flap into position and you will be asked to look at a green flashing light in the laser microscope. A video eye-tracking mechanism compensates for any eye movements for added safety. The actual laser application will again take around 1 minute.

At the end of the LASIK procedure, the LASIK flap is repositioned with fluid.  Eyedrops to avoid infection and control inflammation are applied and will be used for one week.

You are generally comfortable after the LASIK procedure. There may be some stinging for a few hours afterward. Vision usually begins to improve by the next morning.

Most people can work the next day; however, you will be seen in the office for an examination on that day.

The Accuracy of LASIK:

man getting laser eye surgery

In general, more than 95% of patients achieve clear vision as they had with their contact lenses and glasses. In approximately 1 in 20 patients, based on individual healing responses, the entire refractive error may not be corrected or that there might be some over-correction.

If under-corrected, your vision will be clearer without glasses, but less powerful glasses may still be necessary to fine-tune to your best vision. For patients who are over-corrected, especially those patients who are somewhat older, reading vision might be difficult without glasses.

In these cases where vision is not optimal, we typically will consider a touch-up treatment 3 months after the original LASIK procedure to further improve vision.

Side Effects and Complications of LASIK:

There are 2 generally seen side effects immediately after LASIK. First, your eyes may feel dry. Typically, these sensations are mild and are treated with artificial tear drops and resolve over several weeks.  However, dry eye sensations can last in some patients. Second, you will notice a glare/halo around lights at night early after the procedure.

These, too, tend to resolve over the first few days or weeks after the procedure. They can last in a few patients; normally these symptoms can be helped with re-treatment if necessary. Furthermore, older patients, 40 years and older, may require reading glasses after the procedure.

There are also more severe complications that can occur with LASIK, as with all eye surgeries. These will be discussed in depth before your procedure.

Rest assured, though, today’s LASIK procedures at the Cornea and Laser Eye Institute in New Jersey are very safe and we do everything to safeguard your outcome from preoperative analysis to meticulous surgery, to careful postoperative care.


Intralase diagram

We will discuss the expectations for your personal outcome in particular, and what you may reasonably expect to achieve with your vision.

In general, most patients achieved an excellent outcome, although around 5% of patients will undergo a re-treatment enhancement procedure to further improve vision if it is not clear after 3 months.

In addition, other optical side effects include halos around lights and glare, especially at night. Typically, these are early symptoms and improve over time.

These side effects have been much improved with the new Wavelight LASIK procedure. The other group of relatively rare complications may be secondary to problems with the LASIK surgery itself, subsequent corneal healing, and infection. We will discuss these possibilities in detail.

Although most excimer laser treatments today are done with the LASIK technique, some people may be better off with the surface PRK/LASEK procedure. Our preoperative examination and measurements determine our recommendation of the procedure which would be best in your particular situation.

In general, possible benefits of LASIK as compared with LASEK/PRK:

  • Tissue removal beneath a flap rather than at the surface preserves the surface corneal cells (epithelium) with the advantage of faster visual recovery
  • Postoperative discomfort is reduced
  • Tissue removal beneath a flap may decrease the risk of haze or scarring
  • Retreatments are easier to perform

Some risks of LASIK as compared with LASEK/PRK include:

  • Surgical risks (these are rarer with surgeons experienced in LASIK)
  • Damage to the corneal flap
  • Difficulties with the flap postoperatively

The Cornea and Laser Eye Institute is located in our state-of-the-art facility in Teaneck, New Jersey, an easy commute from Paramus, Morristown, Bedminster, and Princeton, and is the preferred destination for LASIK patients across the bridge in Manhattan, New York City.

We are conveniently located 3 miles from the George Washington Bridge which makes it an easy commute from New York City.

Our NJ LASIK patients are encouraged to visit our office and have their questions answered personally. Complimentary consultations are available with Dr. Steven Greenstein so please visit our New Jersey office.  Convenient hotel accommodations are available for out-of-state and international patients.

All Laser LASIK Technology

Intralase LASIK

Wavelight laser

The Intralase femtosecond laser is our preferred technology used to perform the first step in LASIK – the preparation of the corneal flap. In LASIK, the pancake-like flap of the cornea acts to preserve the surface epithelial cells (which are like tiles on a floor) to promote quick healing and recovery of vision (usually overnight).

Taking advantage of an advanced laser technique using a very short pulse, high-speed femtosecond laser, the Intralase creates the flap in a uniquely precise manner.

The procedure is known as IntraLASIK, or more popularly as All-Laser or Bladeless LASIK. Here at the Cornea and Laser Eye Institute, we use the 4th generation 150 kHz Intralase FS laser.

The Intralase laser places over a million microscopic, low energy spots that split the cornea layers to prepare the flap to meticulous specifications. Intralase is performed with numbing eye drops and is a generally comfortable procedure.

Laser application takes less than a minute. The corneal flap then is carefully lifted by the surgeon, exposing interior layers of the corneal structure.

After preparation of the flap, a second laser (the Wavelight excimer laser) sculpts the corneal tissue by removing a small amount of tissue from the corneal bed beneath the flap (analogous to removing a “tissue contact lens”).

At the end of the procedure, the corneal flap is repositioned. When the flap is replaced, it lies in the bed of excimer laser removed tissue, causing the surface to change shape with the effect of decreasing nearsightedness, farsightedness, or astigmatism.

At the end of the procedure, you will be asked to keep your eyes closed for 30 minutes. You will go home with clear, protective eye goggles and use eye drops to avoid infection and control inflammation for one week.

Most people are generally comfortable after the Intralase LASIK procedure. Vision usually begins to improve the morning after the treatment. Most people can drive and work the next day depending on their occupation; however, you will be seen for an examination on that day.

Restrictions include (1) no eye makeup for 3 days, (2) no swimming for 2 weeks, and (3) no eye rubbing for 2 weeks. Sports goggles should be worn when doing contact or projectile sports for one month.

Although vision improves in the first day or two, there may be changes over the next few weeks or months. You will generally see us for visits one day, one week, and 3 months after the procedure. Some patients who are overcorrected or undercorrected can retreat with “enhancement” procedures after the 3-month examination.

Other Applications: Intralase is also used to prepare corneal channels for the Intacs procedure for keratoconus. It may also be used in a number of rehabilitative procedures of the cornea, such as full-thickness and partial-thickness cornea transplant techniques in patients with a variety of corneal problems.

Laser-assisted corneal transplants like this are known as Intralase Enabled Keratoplasty (IEK) or femtosecond laser-assisted corneal transplantation (FLACT).

The Cornea and Laser Eye Institute is located in Teaneck, New Jersey, an easy commute from Paramus, Bedminster, and Morristown, and is conveniently located for LASIK patients across the bridge in Manhattan, New York City, Westchester, and Connecticut. Our NJ LASIK patients are encouraged to visit our office and have their questions answered personally.

Wavelight Excimer Laser System

The Wavelight Eye-Q excimer laser, is a self-aiming, small spot (“flying spot”) laser system for the correction of nearsightedness, farsightedness, and astigmatism. At CLEI, we are pleased to offer this laser technology to our patients.

The Wavelight laser combines both eye tracking and small beam corneal shaping. The built-in eye tracker automatically follows any eye movements during the laser procedure. This allows the system to more accurately aim the laser beam and correct for any movement of the eye during the procedure.

Unlike other laser systems in current use, the Wavelight system uses a very small laser beam of less than 1 mm to shape the cornea. This allows for treatment of a large range of eye refractive problems and also allows the surgeon to choose a treatment size best for your eye.

The laser beam is moved rapidly across the corneal surface in a computer-controlled pattern of tiny overlapping spots. The amount of corneal tissue removed with each spot is very small, less than the thickness of a single human hair.

This changes the shape of the surface of the eye to correct nearsightedness and astigmatism and helps to produce an extremely smooth postoperative corneal surface which may reduce side effects and improve visual recovery.

In addition, by measuring and correcting all eye movements during the laser procedure, the Wavelight system maintains accurate placement of the laser beam, an additional safety feature. At the same time, your surgeon will carefully monitor your eye on a computer screen which provides additional control.

The Wavelight laser can be used for LASIK, LASEK/PRK, and Intralase procedures. We will discuss with you, in-depth, if a procedure using the Wavelight system fits your particular needs.

In-Depth Laser Vision Correction Articles and Studies by our doctors:

LASIK: A Step-by-Step Surgical Approach (adapted from Dr. Hersh’s textbook Ophthalmic Surgical Procedures)


Surgical correction of natural myopia, hyperopia, and astigmatism
Select cases of postsurgical myopia, hyperopia, and astigmatism
Select cases of presbyopia management with a monovision goal


Keratoconus and forme fruste keratoconus
Collagen vascular diseases and inflammatory ocular diseases
?Herpes keratitis
Epithelial basement membrane dystrophy

Preoperative Procedure

  1. Discontinue soft contact lens wear at least 1–2 weeks and rigid contact lens wear 2–4 weeks preoperatively. Confirm the stability and regularity of corneal topography.
  2. Patients should not wear eye makeup on the day of the procedure.
  3. Treat preexisting dry eye and blepharitis. Consider nonpreserved lubricants, lid hygiene, punctual plugs, topical cyclosporine, and oral doxycycline for blepharitis.
  4. Ensure appropriate corneal thickness with an ultrasonic pachymeter.

Note: Corneal thickness minus flap thickness minus ablation depth should be > 250 μm to minimize the risk of corneal ectasia.


  • Lid speculum
  • Gentian violet marking pen (± 3 mm optical zone marker or Sinskey hook)
  • Cellulose sponges
  • Microkeratome or femtosecond laser
  • LASIK or cyclodialysis spatula
  • LASIK irrigating cannula

Operative Procedure

  • For lasers requiring pupil dilation, administer tropicamide 1% ± phenylephrine 2.5%. Otherwise, no dilation.
  • Prep and drape operative eye.
  • Place lid speculum.
  • Create a LASIK flap.

Postoperative Procedure

  1. Place protective shields or goggles until the patient is examined on postoperative day 1. Continue eye protection for 2 additional nights when sleeping.
  2. Corticosteroid drops 4 times per day for 1 week.
  3. Topical antibiotic 4 times per day for 1 week.
  4. Nonpreserved lubricants as needed.
  5. Continue dry eye/blepharitis management as needed.
  6. Explain postoperative management to patients.

Follow-up Schedule

  1. Postoperative day 1: General examination with attention to flap striae. If significant striae are present, reposition the flap in the operating room.
  2. Postoperative week 1: General examination with attention to flap, assess for any infection of diffuse lamellar keratitis
  3. Month 1
  4. Month 3 (full exam to assess the status and consider retreatment if necessary)
  5. Months 6, 12 as necessary

LASIK Complications

Intraoperative Flap Problems:

  1. Short flap
  2. Thin flap
  3. Buttonhole in flap
  4. Free flap

Early Postoperative LASIK Complications

  1. Slipped flap or flap macrostriae
  2. Epithelial defects or sloughing
  3. Iris tuck by the intraocular lens

Intermediate-Term LASIK Complications

  1. Diffuse lamellar keratitis (DLK)
  2. Microbial keratitis
  3. Microstriae
  4. Epithelial ingrowth

Late-Term LASIK Complications

  • Over- and under corrections
  • Induced astigmatism
  • Induced topography irregularities
  • Corneal ectasia and keratoconus

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