Patient Information & Informed Consent · Refractive Surgery

Laser Vision Correction – Femto-LASIK, CLEAR & PRK

You are considering laser vision correction to reduce your dependence on glasses or contact lenses. This interactive form explains the three techniques, the expected outcome, the healing process, and the possible risks. Please click through every item – the consent section at the end only unlocks once all information has been opened and confirmed as read.

Reading progress
0 %
01

How laser vision correction works

The cornea is the clear front window of the eye, and its shape has a major influence on the eye's focusing power. In laser vision correction, the cornea is reshaped to reduce the refractive error: in myopia it is flattened, in hyperopia its curvature is adjusted to increase focusing power, and in astigmatism it is reshaped more in one meridian than another.

1 2 3 4 5

Explore the eye

Tap each of the five numbered points to understand where each laser technique works – the corneal surface, the flap, the lenticule – and why reading glasses may still come with age. All five points must be viewed.

All three procedures work only on the cornea – the rest of the eye is not operated on.

Laser vision correction can treat short-sightedness, long-sightedness, and astigmatism, depending on the individual eye, corneal thickness, corneal shape, prescription, age, visual needs, and medical suitability. It has been performed successfully for decades. However, it is still surgery on a delicate optical structure: no surgical result can be guaranteed, and glasses, contact lenses, enhancement treatment, or other procedures may still be necessary in some cases. Importantly, the procedure does not stop the natural ageing of the eye – from around the mid-forties, most people develop presbyopia and near vision becomes weaker.

02

The three procedures

Each technique has specific advantages, limitations, recovery patterns, and risks. The best procedure is selected individually after detailed examination. Click all three cards.

Femto-LASIK Flap-based

A thin corneal flap is created with a femtosecond laser; an excimer laser reshapes the tissue underneath; the flap is repositioned without stitches.

Usually provides fast visual recovery – many patients see much better within one or two days. Mild dryness, foreign body sensation, fluctuating vision, glare, or light sensitivity can occur during healing. Suitable with sufficient corneal thickness, regular corneal shape, stable refraction, and an appropriate prescription range.

Advantages

  • Fast visual recovery, usually little discomfort
  • High accuracy in suitable eyes
  • Well-established technique
  • Treats myopia, hyperopia, and astigmatism
  • Enhancement possible in many cases if enough tissue remains

Limitations

  • Creation of a corneal flap
  • Temporary weakening of corneal biomechanics
  • Risk of flap-related complications
  • Possible dry eye symptoms
  • Not suitable for every cornea or prescription

CLEAR Lenticule

No flap: a femtosecond laser creates a thin lenticule inside the cornea, which is removed through a small incision.

Removing the lenticule changes the corneal shape and corrects the refractive error. Mainly used for myopia and astigmatism, depending on the treatment range and individual suitability.

Advantages

  • No large corneal flap, only a small incision
  • Potentially less disruption of corneal surface nerves
  • Good biomechanical stability compared with flap-based procedures
  • Usually comfortable healing

Limitations

  • Visual recovery sometimes slightly slower or more variable than Femto-LASIK
  • Enhancement options can be more complex than after LASIK
  • Currently less suitable for certain hyperopic corrections
  • Dry eye, glare, halos, residual error, or regression can still occur

PRK Surface

The superficial corneal skin layer (epithelium) is removed; the excimer laser reshapes the surface; a bandage contact lens protects the eye while the epithelium heals.

No flap is created – useful in selected patients with thinner corneas, higher trauma risk, certain occupational requirements, or eyes where a flap-based procedure is not ideal.

Advantages

  • No corneal flap – avoids flap-related complications
  • Useful in selected thinner corneas
  • Well-established long-term procedure
  • Suitable for selected patients where LASIK or CLEAR is not recommended

Limitations

  • Slower visual recovery than Femto-LASIK
  • More discomfort during the first days
  • Bandage contact lens and longer use of drops
  • Possible haze formation, greater dependence on wound healing
  • Final stability may take several weeks to months

Choosing the right procedure

There is no single best procedure for every patient. The choice depends on prescription, corneal thickness, topography and tomography, tear film and dry eye status, pupil size, age, profession and hobbies, contact sports or trauma risk, previous eye surgery, expectations regarding recovery speed, risk tolerance, enhancement possibilities, and long-term corneal safety. In some cases, laser vision correction may not be recommended at all – alternatives include glasses, contact lenses, ICL/IPCL implantation, refractive lens exchange, or no surgery.

Before surgery: assessment & your information duties

Detailed measurements are required: refraction (with cycloplegia if needed), corneal topography and tomography, corneal thickness, pupil size, tear film and dry eye evaluation, retinal examination if indicated, and higher-order aberrations in selected cases. Contact lenses temporarily change the corneal shape and may need to be stopped before the final measurements, according to the clinic's instructions.

Please inform your doctor about any eye disease, systemic disease, medication, autoimmune disease, pregnancy or breastfeeding, previous herpes eye infection, keloid tendency, or previous eye surgery.

03

What you can realistically expect

Click all three cards – they cover the outcome, the possibility of a second treatment, and the effect of ageing.

Expected outcome Goal

Most suitable patients achieve very good uncorrected vision.

The aim is to reduce dependence on glasses or contact lenses. However, perfect vision without glasses cannot be guaranteed. Some patients may still need glasses for night driving, reading, fine work, computer use, or certain visual tasks. The final result depends on the preoperative prescription, corneal healing, tear film, pupil size, ocular surface, and individual biological response.

Laser correction does not create a perfect or "supernormal" eye – the goal is a meaningful improvement in unaided vision, not a guarantee of perfect vision under all conditions.

Enhancement ≈ 2–5 %

In some cases, a second laser treatment (retreatment) may be required.

The approximate enhancement rate is often in the range of 2 to 5 percent, depending on prescription, technique, healing response, age, dry eye, and other factors. Needing an enhancement does not automatically mean the eye was measured or treated incorrectly – even with careful planning, some eyes heal differently from the expected average.

Reasons include residual short-/long-sightedness or astigmatism, regression, individual healing, epithelial remodelling, dry eye, high preoperative prescription, or corneal biomechanics. Enhancement is only possible if the eye is suitable and enough safe corneal tissue remains; it may be performed as flap lift, surface treatment, PRK, or another technique. In some cases enhancement may not be recommended – glasses or contact lenses may then be the safer option.

Presbyopia From mid-40s

Laser correction does not stop the natural ageing of the eye.

From around the mid-forties, the natural lens loses flexibility (presbyopia) and near vision becomes weaker. A patient with excellent distance vision after laser correction may still need reading glasses later in life – this is not a failure of the treatment, but a normal age-related change.

Options such as monovision or blended vision may be discussed in selected patients, but they are not suitable for everyone and may affect depth perception or night vision.

Normal healing symptoms: burning, tearing, foreign body sensation, light sensitivity, fluctuating or blurred vision, dry eye symptoms, glare, halos, starbursts, reduced night vision, mild discomfort, and redness are common after surgery. They often improve during healing – dryness and visual fluctuation can last for several weeks or months, especially in predisposed patients.
04

Possible risks and complications

Laser vision correction is usually very successful – but as elective surgery on the eye, every risk must be known to you. Open every single item and confirm it with the button inside. Your consent is only valid once all items have been confirmed as read.

Important: Any sudden worsening after surgery must be reviewed urgently. Warning signs of infection: increasing pain, increasing redness, worsening vision, discharge, increasing light sensitivity. Warning signs for the retina: flashes of light, many new floaters, a curtain-like shadow, or sudden loss of vision. Please contact the clinic immediately in these cases.
05

Medication, follow-up, and behaviour after surgery

After surgery, eye drops must be used exactly as prescribed – these may include antibiotics, anti-inflammatory or steroid drops, and lubricants. Do not stop or change medication without medical advice. Follow-up visits monitor healing, visual recovery, intraocular pressure, corneal clarity, epithelial healing, flap position (if applicable), and refractive stability. The exact restrictions differ depending on whether Femto-LASIK, CLEAR, or PRK was performed.

Avoid in the early period

  • Rubbing the eyes
  • Swimming pools and sauna
  • Eye make-up for the recommended period
  • Dusty or dirty environments
  • Direct trauma to the eyes
  • Stopping or changing drops on your own

Please do

  • Use eye drops exactly as prescribed
  • Protect the eyes from trauma
  • Use sunglasses if light sensitive
  • Attend all follow-up appointments
  • Contact the clinic urgently if symptoms worsen
06

Alternatives to laser vision correction

Each option has its own advantages, limitations, and risks:

Glasses Contact lenses No surgery ICL / IPCL implantation Refractive lens exchange (selected older patients) Cataract surgery (if cataract is present) Monovision with contact lenses or laser (selected cases)
07

Did you understand everything? – Quick check

Three short questions – all three must be answered before the consent section unlocks.

1. Does laser vision correction prevent the need for reading glasses with age?

2. What does an enhancement (second treatment) mean?

3. What is the main difference between the three procedures?