Everything to Know About Femto Lasik

What is Femto LASIK?

Femtosecond-assisted (Femto) laser in-situ keratomileusis (LASIK) is a type of laser eye surgery. This method, along with other refractory surgeries, is used to reshape the cornea of the eye in an effort to resolve vision problems.

Keratomileusis, or the sculpting of the cornea as a way to correct refractive errors, was first developed in 1948 using a small surgical tool with an oscillating blade called the microkeratome.

This first method, using a mechanical tool, was known as anterior lamellar keratoplasty (ALK). In the late 1980s and early 1990s, technology for this procedure improved.

The Femto laser, developed in the early 1990s, allowed surgeons to create the corneal flap used in LASIK with a laser rather than a mechanical cutting tool. After surgery, the flap can be replaced without sutures, allowing for quicker healing.

Types of laser surgery

There are two main types of laser surgeries that are now used to reshape the cornea:

Who is the ideal candidate?

To be a candidate for Femto LASIK you must meet the following criteria:

  • 18 and older: LASIK surgery of any type is only approved for use in adult patients.
  • Stable vision: You cannot have LASIK surgery is you have had a change in your glasses or contact lens prescription over the past year, take medications that may change your vision, or have hormonal fluctuations that can affect your vision, such as breastfeeding or diabetes.
  • Good wound healing: You must not have any conditions or take any medications that may prevent proper healing.
  • Thin cornea: People with particularly thin corneas may be at increased risk of blindness with a LASIK procedure.
  • Previous refractory surgeries: You may be prevented form having Femto or other types of LASIK surgery if you have had previous refractory surgeries or procedures.
Conditions that may prevent you from having the surgery

Certain diseases or conditions may warrant further discussion with your doctor or prevent you from being a LASIK candidate all together. These include:

  • blepharitis
  • dry eyes
  • glaucoma
  • herpes simplex
  • herpes zoster
  • iritis
  • keratoconus
  • ocular hypertension
  • presbyopia
  • uveitis

How much does Femto LASIK cost?

One of the drawbacks of refractive surgery is that it is seen as an elective procedure, and therefore not covered under most vision insurance plans.

You may, however, be able to use a health savings account (HSA) or flexible savings account (FSA) to pay for all or a portion of the procedure. Some insurance plans and LASIK centers may also offer discounts depending on your employer or insurance provider.

On average, LASIK surgery costs about $1,000 to $3,000 per eye. Femto LASIK usually costs more, because of the higher-end technology used over traditional LASIK. Other factors that could influence your cost are:

  • location
  • how much your vision needs to be corrected
  • the skill of the surgeon

Beware of “bargain” deals, as these usually have hidden costs, use inexperienced surgeons, or rely on outdated technologies. Be sure to ask your surgeon what costs are included during your initial consultation. Typical packages may include:

  • initial examination and testing
  • all costs associated with the procedure itself
  • post-procedure appointments and medications
  • follow-up procedures as required

How does Femto LASIK work?

To understand Femto LASIK, you have to understand how vision problems develop and how refractive surgery helps. Refractive errors occur when the eye has trouble bending and focusing light. Types of refractive errors include:

  • Myopia: Trouble seeing far away, sometimes called nearsightedness. This condition occurs when your cornea has a steeper shape, so refractive surgery reduces the curvature of the cornea to correct it.
  • Hyperopia: Trouble seeing things that are close, sometimes called farsightedness. In this condition, the cornea is too flat, and refractive surgery is used to increase the curvature of the cornea.
  • Astigmatism: Imperfections in the shape of the cornea. This condition is caused by irregular curving of the cornea, and surgery can be used to reshape the irregular areas.
  • Presbyopia: Loss of elasticity in the eye due to aging. This is a condition that occurs with age, and happens with the lens inside the eye becomes more stiff and loses flexibility. While refractive surgery can help correct this problem in some cases, it can also prevent you from being a candidate for refractive surgery.

Not all of these problems can be corrected by refractive surgery. Refractive surgery only works to correct problems that can be resolved by reshaping the cornea.

When refractive surgeries are used to correct these problems, a cut is made on the surface of the eye, and a laser is used to reshape the cornea.

Procedure for Femto LASIK

On the day of surgery, the following steps will take place:

  • You will be brought to a procedure room and placed in a reclining chair.
  • You will lie on your back under the laser system and a computer screen.
  • Numbing drops will be placed into your eyes.
  • A machine called an eye speculum will be used to keep your eyelids open during the procedure.
  • A suction ring is then centered over the pupil and suction is applied.
  • A glass lens to hold the globe of the eye steady and flatten the cornea.
  • Once the laser has fixated on the surgical area, your surgeon administers the first treatment.
  • The laser pulses to create a flap in the surface of the cornea and suction is released.
  • Once the flap is peeled back, a precise excimer laser uses ultraviolet rays to reshape the cornea as required to resolve your condition.
  • You may hear a ticking sound or smell something burning during this part of the procedure.
  • In Femto LASIK, the flap is replaced once reshaping is complete
  • The flap will heal in place without sutures.

The entire procedure should take no more than 30 minutes for each eye. Be sure to have someone with you to drive you home after the procedure.

Are there any risks or side effects to this type of LASIK?

Like traditional LASIK, Femto LASIK comes with risks, and people with certain characteristics or conditions may not have the procedure. Certain careers may also require approval for, or prohibit, refractive surgeries due to the lack of data on long-term outcomes.

As with any surgical procedure, there are risks to Femto LASIK. Every LASIK procedure carries risks of:

  • treatment may be minimally effective or not help at all
  • permanent vision loss
  • reduced effectiveness over time
  • ongoing vision symptoms like halos around lights
Complications specific to Femto LASIK

Learn more

There are also some complications that are specific to Femto LASIK. These include:

  • Opaque bubble layer (OBL): This occurs when gas bubbles accumulate in the flap and interfere with the ability of the laser to work properly.
  • Transient light sensitivity syndrome (TLSS): This problem can arise days or weeks after surgery and can result in extreme sensitivity to light and vision problems. Topical steroids may be used to treat this condition.
  • “Rainbow glare: ” This is cause by tiny irregularities on the back of the flap created during surgery. It can result in the appearance of colored bands of light in the field of vision when looking at a white light source.

What to expect after Femto LASIK

After your Femto LASIK surgery, you may experience:

  • discomfort like mild pain, burning, itching, or irritation
  • watering or tearing
  • hazy or blurred vision
  • sensitivity to light
  • halos or glare around lights
  • redness or bloodshot eyes

These symptoms will usually last a few days, so you may want to take some time off work.


Your doctor should give you instructions on follow-up care and recovery that may include the following:

  • You will wear an eye shield for the first 24 to 48 hours after the procedure to prevent your from scratching or rubbing your eye and dislodging the flap.
  • You should have a follow-up appointment 24 to 48 hours after surgery where your surgeon will remove the eye shields and check your vision.
  • You may receive eye drops to take home to prevent infection or inflammation.
  • You will be instructed to not wear contact lenses on the operative eye even if your vision is blurred.
  • You should avoid lotions, creams, and cosmetics for two weeks after surgery.
  • Your doctor will also advise you to limit activities like non-contact sports and other strenuous activities for one to three days after the procedure.
  • Swimming or hot tub use should be avoided for one to two weeks after surgery.
  • Contact sports and other strenuous activities should be avoided for at least four weeks after your surgery.
  • Your vision may continue to fluctuate for the first few months after surgery. It can take three to six months to realize the full effect of the procedure.
  • Your surgeon should schedule regular follow-up visits with you for at least six months after the surgery.

Preparing for Femto LASIK

Before your Femto LASIK surgery, you should meet with your surgeon to discuss your goals, any risk factors, and your desired results. Your surgeon should advise you of realistic expectations, risks, and costs for the procedure. If you wear contact lenses, You may be asked to leave them out for 1-3 weeks depending on the type of lenses you wear.

Before the day of your procedure, your surgeon will perform a complete exam and scan your eye. This scan will be used to guide the laser.

You will want to check with your employer to make sure your job requirements will not prevent your from having refractive surgery. You should also review the cost of the procedure, any insurance coverage or discounts, and determine how you will pay for the surgery.

Be sure to have someone available to take you to and drive you from the procedure. You will also be advised to stop using cosmetics, creams, or lotions near the eye for at least a day before your surgery.

Femto vs. Smile and PRK

There are several types of refractive surgeries, and each has key differences that set them apart. The goal of each procedure is to reshape the cornea with a laser to resolve vision problems. How the cornea is accessed is different for each procedure.

  • In traditional LASIK surgery, a flap is made instead of completely removing the top layer of the cornea. This flap is made with a tiny cut by a mechanical instrument.
  • In Femto LASIK, a flap is created, but it is done using a laser rather than a cutting tool.
  • With PRK surgery, the top layer of the cornea is completely removed.
  • SMILE (Small Incision Lenticule Extraction) is similar to Femto LASIK, but the laser incises an even smaller area.

The bottom line

Femto LASIK can heal faster and result in fewer complications than traditional LASIK because it uses a laser rather than a mechanical cutting tool to make a small flap in the surface of the eye.

The end goal is to reshape the cornea with a laser to resolve vision problems like nearsightedness and farsightedness. As with any procedure, there are risks, and these procedures can be costly and are rarely covered by insurance.

Be sure to talk about your risks, the costs, and realistic expectations before undergoing LASIK surgery.

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