Frequently asked questions about laser eye surgery

ZEISS technology is leading the way in a range of sectors, from medical technology to high-precision vision care.

You may know ZEISS from your last visit to the optician, as ZEISS is a leading manufacturer of spectacle lenses. ZEISS’ expertise also extends to camera lenses and binoculars as well as observation and rifle scopes. In fact, ZEISS optics in the James Webb Space Telescope allow humanity to see into the furthest reaches of the universe.

But the company is more than that. With a history that stretches back over 175 years, ZEISS is an established, world-leader in advanced medical lasers and scientific optics. With its origins in Germany, the company now employs more than 35,000 people at 160 locations in 50 countries. Research and development are undertaken in 27 specialist research and development facilities to ensure ZEISS is always at the forefront of technology.

If your eyesight has been stable over the past year (usually after the age of 18), you wear glasses or contact lenses to correct your vision and are otherwise healthy and not pregnant, you may be a candidate for laser eye surgery. Your eye doctor will be able to tell you if this is a viable option for you.

One of the most important parts of a laser eye surgery is finding the right clinic. There are many factors to consider, including the doctor’s experience, and the technology he or she uses. Visiting doctors, researching surgeons and comparing them might help when choosing the doctor or clinic you feel most comfortable with. When consulting a doctor, it is good to prepare your questions beforehand.

Yes, both eyes can be treated during the same session. Your eye doctor will decide whether this is possible.

During PRK, the patients experience minimal discomfort or pain. For the Femto-LASIK procedure, a thin flap in your cornea is created using another (femotosecond) laser. You may feel some pressure and some discomfort at the beginning of flap creation.
During Lenticule Extraction with ZEISS SMILE, you may feel some sensation but should not feel pain due to the numbing drops applied before and during the treatment.

Laser eye surgery is usually permanent, but if your prescription changes in the future, you may need to wear glasses or contact lenses, or consider an enhancement surgery.

There are two significant differences between these types of laser eye surgeries.

With LASEK the inner layers of the cornea are exposed. The doctor applies an alcohol solution to loosen the epithelium, which is temporarily pushed aside. The doctor then applies the excimer laser, an ultraviolet laser used in eye surgery, to remove corneal tissue by ablation. During LASEK, this is done at the exposed top layer of the cornea.

With LASIK, a flap is cut with a mechanical device or a laser, folded back for surgery, and then repositioned when surgery is complete. The layer of corneal tissue ablated in LASIK occurs in the stroma, a sublayer of the cornea.

The second difference is the recovery time and patient experience. LASIK patients typically have a much shorter healing period with less discomfort.

SMILE is designed to correct myopia, astigmatism or a combination of the two, but is currently not an option for farsightedness (hyperopia) yet.

The nature and degree of the refractive error, and the curvature and thickness of the cornea also play a role.

Your profession and hobbies are also important. If you often participate in strenuous contact sports, your doctor might recommend a treatment with SMILE.

As with other laser vision correction methods, you will first need to undergo a detailed eye examination to determine whether you are a suitable candidate.

Together, you and your doctor can chose the best option to suit your needs.

Your ophthalmic surgeon will provide you with a list of instructions about your procedure, including when to stop wearing your contact lenses, what to eat on the day, what to wear to your procedure and when to administer your post-op, prescription eye drops. Please note, you will need to arrange for someone to take you home after the procedure.

Following the procedure, you should avoid rubbing or touching your eye. Some ophthalmic surgeons may recommend wearing eye shields while sleeping for a day or so following your treatment.

In most cases, following the surgery with ZEISS SMILE, patients enjoy improved vision immediately – and it will even get better over the next few days.

However, you will not be able to drive after the procedure, so you will need to arrange for someone to take you home. Please also talk to your consultant for any details that might be applicable in your particular circumstances.

Your surgeon will use the latest ZEISS medical technology and software during your corrective eye procedure. Lenticule extraction with SMILE® is performed on VisuMax® from ZEISS. The device has a femtosecond laser with produces laser light that lasts just 1⁄1,000,000,000,000,000 of a second. Each laser pulse delivers a quick, precise yet gentle burst of light.

To help the surgeon do their job effectively, ZEISS VisuMax also features high-quality ZEISS microscopes, digital cameras, advanced interactive touch screens and integrated illumination. And for you, the patient, there’s a comfortable, ergonomic couch that supports you throughout the short surgery time.

As with all surgical procedures, you may experience side effects after your surgery. However, vision correction with ZEISS SMILE has been designed to be as minimally invasive as possible. Unlike other laser eye correction, your surgeon only needs to create a small, keyhole opening in your eye. The upper layers of the cornea remain virtually unaffected, which means side effects with ZEISS SMILE are very rare.

However, you should know potential side effects may include:

• Disorders of the cornea, retina and other parts of the eye
• Visual disturbance
• Visual impairment
• Ocular pain

A few patients may also experience some temporary limitations, such as delayed visual recovery.

You should see a difference in your vision almost immediately after your procedure. Follow your consultant’s instructions regarding post-op medication and any restrictions. During the healing process, you should avoid rubbing your eyes. What’s more, you may feel some minor discomfort, such as sensing foreign bodies or blurred vision while your eyes are recovering.

Many patients can resume normal activities such as exercising, wearing makeup, working and playing sport as soon as the next day.

PRK/LASEK procedures have a longer healing time and involve some discomfort until reaching the final stabilized vision result. The stabilization of visual acuity also takes more time.

Lenticule Extraction is the latest advancement of laser vision correction and SMILE has been available since 2011. The technique is known and recognized by medical trade associations related to refractive laser eye surgeries.

The popularity of SMILE continues to grow, and over 2,500 surgeons have already successfully treated millions of eyes.

Femtosecond laser technology is clinically proven and is used for Femto-LASIK as well as cataract surgery. SMILE is the latest development using this laser technology for laser vision correction.

It has been performed in controlled clinical studies since 2007 and has been commercially available since 2011. The first SMILE-patients have been monitored for over ten years post-treatment. It is currently established in over 80 countries worldwide.

The difference between the Femto-LASIK and the classic LASIK method is the way the flap in the cornea is created. A laser is used to cut the flap in Femto-LASIK. With the classic method, the surgeon opens the cornea manually with a microkeratome (mechanical device).

The laser can be more precise and predictable in cutting the flap than the manual method with a mechanical device. However, eye surgeons do not have a uniform opinion that one method is more clinically superior than the other. The decision between the two is based on a patient’s existing conditions and the doctor’s preferences.

It is important to follow your ophthalmic surgeon’s advice both before and after the laser eye operation. Always take any medication and use eye drops as directed. While it is impossible to say you will not suffer from any side effects, following your surgeon’s instructions will help minimise any potential complications. Some patients, however, will still feel some mild discomfort (like scratching, tearing, or burning sensations) even if they follow all the instructions given.

Not everyone will end up with 20/20 vision after undergoing LASIK surgery. A global review of LASIK from 2009 however, found that more than 95% of LASIK patients from 1995 to 2003 were satisfied with the outcome of their surgery.

While the reason to get laser vision correction is to reduce your dependence on glasses, you may still need them for certain activities such as reading. If you suffer from severe myopia (near-sightedness), LASIK may not be able to fully correct your prescription and, as a result, you may have problems viewing objects in the distance. What’s more, everyone eventually develops a condition called presbyopia. This occurs when your eyes gradually lose the ability to see things clearly up close and is a normal part of aging. Laser vision correction cannot stop this process, nor does it speed it up. If you start having problems focusing on nearby objects, you should discuss your options with your eye doctor. They may suggest the monovision procedure or simply wearing reading glasses.

Post-surgery, you may experience glare from headlights or halos around street lights when driving at night. These are common side effects, and you may wish to avoid driving for a few days until the symptoms subside.

Yes. Lenticule Extraction with ZEISS SMILE is a minimally invasive procedure that uses a small incision of ~ 4 mm to correct your vision. And, as no flap is created during the operation, there is no risk of flap-related complications. 
Find out more about ZEISS SMILE here and consult your optician, optometrist, or ophthalmologist to see if it is the right choice for you.

The procedure typically takes around 30 minutes, and you can return to your daily activities within a day or two.

Recovery time differs between individual patients, but the flap should be stable within a matter of days. Your vision may take a few days to become stable after the surgery.

Doctors typically require a follow-up exam the day after and one month after surgery to check on your progress.

While recovery times differ from patient to patient, there are some post-op precautions you can take to improve your outcome, such as not rubbing your eye or avoiding dusty environments. Most importantly, you should always follow your doctor’s instructions. These may include using eye drops, other medication or even wearing an eye shield in specific cases. And always use any medication or eye drops as directed as they will help with the quick and safe recovery of your eye.

If you are wondering if astigmatism can be treated with LASIK, the answer is usually yes. There is a common misconception that astigmatism rules out LASIK as an option. However, the fact is that LASIK has been used for many years to treat most types of astigmatism.

As LASIK surgery adjusts the shape of the cornea, it is unsuitable for the less common high levels of astigmatism. Furthermore, astigmatism caused by certain normally rare conditions including keratoconus or pellucid marginal degeneration cannot be corrected by laser eye surgery.

It is difficult to put an exact price on laser vision correction as several factors determine the overall cost. However, many patients see LASIK for astigmatism as a long-term investment in their vision. Over the years, surgery costs are easily recouped against the long-term savings made – e.g. by not having to pay for glasses or cover ongoing contact lens subscriptions.

Bladeless LASIK is a procedure that uses two types of lasers during surgery – a femtosecond laser to create a corneal flap and an excimer laser to shape and correct your cornea. Bladeless LASIK differs from the traditional LASIK procedure, which uses an oscillating blade called a microkeratome to create the flap.

A flapless alternative to LASIK is Lenticule Extraction with ZEISS SMILE. As no flap is created and an incision of ~ 4 mm is made in the cornea, the procedure preserves corneal tissue and overall eye strength is maintained. ZEISS SMILE can correct near-sightedness with or without astigmatism.

If you have thin corneas, PRK may offer a suitable alternative laser eye correction method. Instead of creating a corneal flap, during PRK the surgeon completely removes the upper layer of the cornea called the epithelium and afterwards performs the laser vision correction procedure. After surgery, the epithelium grows back naturally, usually within a few days.

Presbyopia and hyperopia both result in blurred and unclear near vision. However, presbyopia is a result of the ageing of the lens, whereas hyperopia is a result of an eye that is not perfectly shaped. Depending on the severity of the issue, glasses, contact lenses, or laser eye surgery are some of the options available. You should consult your optician, optometrist, or ophthalmologist to establish your condition and discuss the best way to treat it.

LASIK does not cause presbyopia. What’s more, LASIK doesn't make presbyopia worse or accelerate its progress. Patients typically notice the condition when they are in their forties. Presbyopia is a natural occurrence due to ageing and can occur regardless of whether you have had laser eye surgery earlier in life.

According to the FDA, which regulates laser vision correction in the US, full stabilisation of vision can take as long as 3 – 6 months after LASIK surgery. However, there is a minimally invasive procedure available, ZEISS SMILE, which involves making a small incision that’s ~ 4 mm. As there is no need to create a flap or remove the outer layer of the cornea, recovery times with ZEISS SMILE are in line with minimally invasive refractive procedures and can be shorter compared to LASIK.

The surgery most suitable for you also depends on your prescription and other pre-existing conditions – such as dry eye syndrome. If you are ineligible for LASIK, a possible solution could be either PRK/LASEK or SMILE. Both applications might be alternatives for those with thin corneas or more severe cases of myopia. Candidates also include those who may be at a high risk for flap complications (e.g certain jobs, sports and hobbies that are strenuous or involve contact). Your eye doctor will be able to recommend the best laser eye surgery procedure for your individual case.

PRK surgery has good success rates, but like any surgery, it is not risk-free. Some possible complications include infection and inflammation of the eye, glares, halos and starbursts, as well as corneal haze and dry eyes. Many of these complications are treatable with medication, however, some of them may require additional surgery. You should contact your ophthalmic surgeon immediately if you notice any signs of infection, redness of the eye, pain, discharge, or decreased vision.

It normally takes your eye around three days to grow back a new layer of epithelium cells over your cornea. After that, your doctor will remove the bandage contact lens, and you should be able to see more clearly. It will then take about a month for most patients´ vision to stabilize, and your eye may feel uncomfortable, gritty and itchy at times after the PRK surgery.

Compared to the other laser vision correction techniques, the PRK has longer recovery time as there is an extra step involved in the healing process; the corneal epithelium, which is completely removed during the treatment, has to grow back naturally. This process takes about three days, so this has to be added to the overall recovery time.

Yes! Depending on your preference and your ophthalmic surgeon’s recommendation, the PRK procedure can be performed on one or both eyes in a single treatment.

One of the most popular laser vision corrections available, LASIK, involves your surgeon creating a corneal flap to correct your vision. This may not be suitable for every patient, particularly as it runs the risk of the flap being dislodged or infected post-surgery. However, PRK is not the only flapless option. Lenticule Extraction with ZEISS SMILE offers a flapless, minimally invasive alternative that leverages advanced technology and techniques. If you are considering PRK or LASIK, talk to your eye doctor to see if Lenticule Extraction using ZEISS SMILE would be a more suitable option for your individual needs.

TransPRK (Transepithelial PhotoRefractive Keratectomy) is a similar procedure to standard PRK. Both procedures follow the same steps to correct your vision. However, during the standard PRK, the corneal epithelium is dissolved away using alcohol solution whereas during the TransPRK procdure, your surgeon removes the epithelium layer using excimer laser.

PRK, LASIK and Lenticule Extraction with ZEISS SMILE have proven to be safe and effective procedures to correct astigmatism. Each has its own advantages and disadvantages. PRK procedure may be more advantageous for patients with thinner corneas than LASIK. However, the corneal healing after PRK is usually longer than after LASIK. Lenticule extraction with ZEISS SMILE is an advanced laser vision correction procedure with fast recovery times and without flap-related complications. You should talk to your doctor to determine which procedure is best for you.