Laser Eye Surgery: Vision Correction at the Highest Level

When the term laser eye surgery is mentioned in everyday language, most people think of getting rid of glasses and eliminating refractive errors. However, vision correction and laser eye surgery today are far from being limited to refractive correction treatments alone. With advances in technology, laser treatments play a key role in preserving or restoring vision in numerous eye diseases.

In this article, we present the various laser eye surgery procedures, highlighting that the intervention is not merely a luxury item promising freedom from glasses. Modern ophthalmic laser treatments are in fact the cornerstones of preserving vision, improving its quality, and restoring it.

It is also important to understand that in ophthalmology, “laser” does not refer to a single universal solution. We use entirely different types of laser light and technologically different equipment for refractive vision correction than for the most precise steps of laser cataract surgery. Similarly, different lasers are required for treating various types of glaucoma, posterior capsule opacification, vitreous opacities, or various retinal diseases.

1. Corneal Laser Treatments (Refractive Laser Eye Surgery)

The refractive power of the eye is primarily determined by two factors: the cornea and the lens. Under ideal conditions, these tissues focus light precisely onto the retina. If this focal point is too far forward, the eye becomes myopic (minus diopters); if too far back, hyperopic (plus diopters). A special form occurs when the diopters shift in opposite directions along two perpendicular axes—this is called astigmatism (cylindrical diopters).

During refractive correction procedures, the laser alters the curvature of the cornea, thereby changing the eye’s total refractive power—its diopters—and bringing the focal point closer to the retina. The various procedures can be fundamentally divided into two major technological groups:

Surface Treatments (PRK, No-Touch PRK)

Laser platform: excimer laser

The common feature of surface procedures is that the excimer laser performs the refractive error correction on the corneal surface. Since no flap is created, the structural stability of the cornea is maximally preserved. This is one of the longest-established vision correction laser eye surgeries.

• PRK (Manual Epithelial Removal): The surgeon mechanically removes the epithelial layer, then the excimer laser performs the correction. Here, either a standard profile or a wavefront/aspheric profile that also corrects the eye’s individual optical aberrations can be selected.
• No-Touch PRK/Trans-PRK (Laser Epithelial Removal): The most modern surface technology, where no instrument touches the eye. The excimer laser removes the epithelium as well, then continues seamlessly with the refractive error correction. Here too, there are differences in the customization of the profiles.

Deep Treatments (Flap and Pocket Procedures)

Flap Procedures (LASIK, FemtoLASIK)

Laser platform: excimer +/- femtosecond laser

In flap procedures, a thin corneal section is almost completely cut on the corneal surface—creating a flap—under which the treatment is performed, and at the end it is folded back. This is one of the most commonly performed refractive correction laser eye surgeries.

• LASIK (Single-Laser): The flap is created with a precision mechanical device (microkeratome), followed by application of the excimer laser. Since the widespread adoption of modern femtosecond lasers, this method is now used less frequently.
• FemtoLASIK (Dual-Laser): The protective flap is created with a femtosecond laser, then the excimer laser treatment is performed in the underlying layer.

Pocket, Lenticule-Extraction Procedures (KLEx: SMILE, CLEAR)

Laser platform: femtosecond laser

In one of the most modern refractive laser eye surgery procedures, only a femtosecond laser is used for the treatment. In this case, there is no need for surface epithelial removal, so healing and recovery are rapid. However, there is also no need to cut a wide flap, so the eye’s biomechanical stability remains better and the risk of dry eye is also lower.

The laser first isolates a small piece of tissue (lenticule) inside the cornea, then makes a small incision in the cornea through which the lenticule is removed.

2. Laser Lens Surgery (Femto-CLE, FLACS)

Laser platform: femtosecond laser +/- ultrasound

Clear Lens Extraction (Femto-CLE)

Although cornea-based laser treatments are extremely popular, the vision correction revolution is now also present in lens surgery. It is important to recognize that laser eye surgery performed on the cornea is primarily an ideal solution for achieving freedom from glasses up to age 45. After that, the eye’s natural lens gradually loses its elasticity—this is presbyopia, which the international literature now often refers to as dysfunctional lens syndrome (DLS).

Due to the loss of lens elasticity, the eye can no longer focus between different distances, so it requires different diopters for almost every distance. Therefore, laser treatments affecting the cornea no longer provide a true solution at this age, although certain attempts exist for this as well.

However, since these treatments do not address the source of the problem—the aging lens—the results often fall short of expectations or can only be enjoyed for a short time. Between ages 45 and 55, the emphasis therefore shifts toward lens surgery. After age 55, almost exclusively intraocular lens implantation can provide a permanent solution.

With advances in technology, lens surgery is now recommended not only in cases of disease (cataract) but also for vision correction purposes. This is called clear lens extraction (CLE), which in practice is identical to cataract surgery, with the difference that here little or no ultrasound energy is required for lens removal.

Femto-CLE is a laser eye surgery in which we supplement the traditional lens extraction technique with the advantages offered by the femtosecond laser, thereby achieving perfect intraocular lens positioning while reducing the risk of surgical complications.

This procedure therefore enables correction of refractive errors even in older age. With the implantation of modern extended depth of focus or new-generation multifocal intraocular lenses, it can provide lifelong glasses-free vision at all or nearly all distances.

Laser Cataract Surgery (FLACS)

Cataract affects everyone as they age and can only be treated surgically. In traditional, ultrasound-only cataract surgery, the surgeon makes small incisions in the cornea, then creates a circular opening in the lens capsule. The lens is then fragmented with manual instruments and removed with an ultrasound device, so that the appropriately powered intraocular lens can finally be implanted in the clear lens capsule.

In laser cataract surgery (FLACS), the most critical manual steps of the traditional procedure are automated with a femtosecond laser, while ultrasound technology is also retained for lens removal.

During the procedure, the femtosecond laser can perform the following steps:

• Corneal Incisions: To reduce astigmatism, we can make partial-thickness incisions with the femtosecond laser, or if necessary, create the incisions themselves with it.
• Opening the Lens Capsule: With the femtosecond laser, we can create an opening in the lens capsule precisely at the desired location and size, with less tissue stress. This precision is essential when implanting premium (multifocal or toric) intraocular lenses, since perfect vision requires the opening to be the appropriate size and perfectly centered. Most of the time, manual technique will be acceptable, but with laser it is always perfect.
• Lens Fragmentation: With the femtosecond laser, we can dice the cataractous lens into very small pieces before removing it with an ultrasound device. As a result, significantly less ultrasound energy is required during surgery. This makes the procedure gentler on the surrounding tissues, which is especially important for the inner cells responsible for corneal transparency, as postoperative edema is reduced, healing is faster, and vision clears sooner.

Laser cataract surgery technology effectively combines the proven steps of traditional surgical technique with the precision and gentleness of the laser, contributing to better outcomes.

4. Posterior Capsular Opacification Laser Treatment (Capsulotomy)

Laser platform: Nd:YAG laser, Q-switched Nd:YAG laser

In the years following cataract surgery, vision may become cloudy again. This is not a return of the cataract, but the development of so-called posterior capsular opacification, which means that the lens capsule holding the intraocular lens thickens over time and becomes opaque.

Although the symptoms are similar to the original condition, the solution is a quick and painless laser eye surgery that can restore vision almost immediately. However, it matters greatly which device and surgical strategy are used to apply the technology. The following two laser eye surgeries are available for treating posterior capsular opacification.

Traditional YAG Laser Treatment (YAG Capsulotomy)

Laser platform: Nd:YAG laser

By targeting the laser at or directly behind the posterior lens capsule, small explosions are created that directly rupture it, allowing light to pass through to the retina again. This is a reliable procedure, but it carries the risk of irregular rupture (central portion hanging in), detached capsule fragments (floating in the vitreous), and intraocular lens damage (IOL pitting), which can cause additional visual complaints (eye floaters, light scatter, glare, occasionally spotty vision).

Premium Posterior Capsular Opacification Laser Treatment (PRO Capsulotomy)

Laser platform: Q-switched Nd:YAG laser

PRO capsulotomy is a laser eye surgery in which a well-established procedure has been further refined at both the technological and execution levels.

Using the advanced Q-switched Nd:YAG laser device combined with the PRO technique, we can perform a much finer and more predictable treatment. The essence of premium posterior capsular opacification laser treatment is that here we focus the laser shots deeper than the posterior wall of the lens capsule, onto the anterior vitreous, where a shockwave is also generated following the explosion with this laser. By utilizing this, we can create a more regular central opening while maintaining a safe distance from the intraocular lens.

This precision is critical for intraocular lens stability and quality sharp vision, while the risk of lens damage or tissue fragment detachment remains negligibly small. The size and shape of the opening are thus better planned, and the risk of lens damage or tissue fragment detachment remains negligibly small.

5. Glaucoma Laser Treatment (Iridotomy, SLT)

Laser platform: Nd:YAG laser; Q-switched, frequency-doubled Nd:YAG laser

Glaucoma has many subtypes, and in several cases multiple laser treatments are possible. A complete overview would be very extensive. Below, we will discuss the most common forms and the most frequently performed laser eye surgeries.

Angle-Closure Glaucoma Laser Treatment (Laser Iridotomy)

Laser platform: Nd:YAG laser

In this case, vision correction is achieved by eliminating the cause of sudden vision loss. One of the most dangerous types of glaucoma is angle-closure glaucoma, which can lead at any time to a dramatic deterioration—a glaucoma attack. At such times, the suddenly elevated, extremely high intraocular pressure causes the cornea to become edematous, resulting in significant and rapid vision loss.

During YAG iridotomy, a small opening is created in the iris with the traditional YAG laser, allowing the fluid produced behind it to come forward. This immediately equalizes the pressure between the anterior and posterior chambers of the eye, and the intraocular pressure quickly normalizes. This will subsequently function as a “safety valve” and prevent such a situation from recurring.

As the intraocular pressure normalizes, the tension on the tissues gradually decreases, the corneal edema slowly resolves, the edema is absorbed, and vision clears again within a few hours or days.

YAG iridotomy is a laser eye surgery that can be performed not only during a glaucoma attack but also preventively in those whose anatomical features pose a risk of angle closure.

Iridotomy can therefore be considered not only a vision-correcting but also a vision-saving intervention, as it prevents irreversible damage to the optic nerve, which would result in permanent vision loss or blindness. When there is no corneal edema, there is no change in vision after this laser treatment.

Open-Angle Glaucoma (SLT: Selective Laser Trabeculoplasty)

Laser platform: Q-switched, frequency-doubled Nd:YAG laser

In open-angle glaucoma, as part of the treatment, instead of eye drops we can now choose selective laser trabeculoplasty (SLT), in which we use a Q-switched, frequency-doubled Nd:YAG laser for gentle stimulation of the target tissue.

The goal of SLT treatment is to achieve sustained reduction of intraocular pressure and prevent damage to the optic nerve head. This can prevent visual field loss and vision deterioration, although the treatment has no direct vision-improving effect. During the procedure, the laser delivers short, low-energy pulses to the eye’s drainage system, the tissue in the angle (trabecular meshwork). The term “selective” refers to the fact that the laser targets only pigmented cells, thus causing no thermal damage or scarring to the surrounding healthy tissues.

This laser eye surgery initiates a kind of biological cleansing: as a result of the treatment, the body’s own cells (macrophages) “clear out” the blocked channels, improving aqueous humor outflow. The effect of biostimulation and the resulting reduction in intraocular pressure typically occur within 1–2 months.

6. Laser Treatment of Eye Floaters (Laser Vitreolysis)

Laser platform: Q-switched Nd:YAG laser

In the gel filling the eyeball, smaller or larger aggregations often form, which cast shadows on the retina and are thus seen as floating opacities. Over time, the gel-like material inevitably collapses in everyone and separates from the back of the eyeball. This process is called posterior vitreous detachment and leads to the appearance of a particularly bothersome vitreous opacity called a Weiss ring in many people.

These eye floaters cause visual discomfort especially against bright backgrounds, while driving, looking at monitors, or reading. Although previously we could only tell the patient to “get used to it,” modern technology now offers a quick and painless laser solution even in these cases, even if not every opacity can be eliminated with it.

During laser treatment of eye floaters (vitreolysis), we use a reflex-type Q-switched Nd:YAG laser. During vitreolysis, a so-called cavitation bubble and then a plasma sphere form, through which the treated tissue is completely converted into gas and liquid. Although it can be read in several places that in this case we fragment the opacity into smaller pieces, this is incorrect, because unlike the classic YAG laser, here the disturbing particles are vaporized, thereby immediately disappearing from the vitreous and thus from the visual field.

The procedure results in rapid improvement in vision quality, as it frees the patient from the constantly intruding, disturbing shadows, restoring the experience of spot-free vision and improving quality of life.

Among laser eye surgeries, vitreolysis achieves one of the most dramatic changes in vision quality for the patient, especially when caused by a localized opacity.

7. Retinal Laser Treatments (Photocoagulation, Micropulse Treatment)

Laser platform: green laser, yellow laser, subthreshold yellow laser

During retinal laser treatment, our goal is to protect healthy visual tissue and halt pathological processes. The direct or indirect consequence of this is vision correction or preservation of good vision. Today, several modern laser eye surgeries are available, so depending on the nature of the problem, we can apply the most appropriate laser and treatment method.

Scar-Forming Lasers: Photocoagulation

Laser platform: yellow laser, green laser

Among laser eye surgeries, this procedure is based on controlled thermal effect, which purposefully coagulates tissues. With photocoagulation, the laser energy can create predictable, small, and precise scars for the purpose of securing or remodeling the retina. In these cases, the laser treatment primarily has a vision loss prevention effect; visual acuity does not change at that time.

• Retinal Tear Laser Treatment (Laser Retinopexy): If a small hole or tear forms in the retina, it is a serious condition threatening retinal detachment. In this case, the laser creates a series of small scars around the damaged area—essentially “welding it around”—thus firmly securing the retina to its base around the tear. This prevents the tear from spreading and causing retinal detachment, which would result in significant vision loss. The scarring process begins immediately after treatment but is fully completed within a few weeks.
• Panretinal Laser Treatment (PRP, Panretinal Photocoagulation): In more severe conditions, such as diabetic retinopathy or venous occlusion, if new but abnormal vessels form in the eye, the peripheral areas of the retina must be extensively scarred as treatment. As a result of PRP, we can reduce the total oxygen demand of the retina, so the dangerous, fragile vessels close and regress, thereby protecting central, sharp vision. This extensive treatment may narrow the visual field and impair night vision, so it is truly performed only as a last but necessary resort. In this case as well, a few weeks are required for complete scarring.

Biostimulating Lasers: Micropulse Laser Treatment

Laser platform: subthreshold yellow laser

The yellow laser can be used not only in traditional, scar-forming mode but also in so-called subthreshold mode—this is called micropulse laser treatment. During this, the laser light is delivered not continuously but in extremely short bursts, so the tissues have time to cool between “pulses.” While traditional (suprathreshold) mode lasers produce heat and leave scars, in contrast, micropulse laser treatment does not cause burning or destruction of the tissues.

The micropulse laser initiates a complex tissue biostimulation that activates the body’s natural self-healing processes. During this, protective proteins (HSP) are formed, the function of certain cells is enhanced, and metabolic processes are initiated that have anti-inflammatory and fluid-removing effects on the retina.

This laser eye surgery is particularly effective in treating various edematous conditions of the retina. Among micropulse lasers, only the Navilas laser device has an eye-tracking system and a treatment-planning interface, which is especially important for a procedure where otherwise no trace is visible on the retina either during or after treatment.

The Navilas micropulse device is therefore excellently suited for various causes of macular edema (fluid accumulation in the sharp vision area of the retina), or for diseases where subretinal fluid accumulates between the layers, such as in CSCR disease.

Since the treatment is “subthreshold,” meaning it leaves no scar, micropulse laser treatment has no vision-damaging effect and can be safely repeated if necessary. After effective treatment, the fluid accumulation is absorbed and vision improves. The effect of biostimulating laser eye surgery builds up gradually, typically reaching its maximum around 2–3 months.

Summary of Laser Eye Surgeries

We can see, therefore, that in modern ophthalmology, lasers are not suitable for just a single task but fulfill different functions on different parts of the eye for maximum safety. During laser eye surgery, we use the following main laser types:

• The femtosecond laser is the precision “scalpel”: it can create any tissue incision with micron-level accuracy. This is why we use it in the femtoLASIK procedure to create the protective flap, in KLEx technology to create the special pocket and lenticule, or in laser cataract surgery (FLACS) to create the opening in the lens capsule and gently fragment the lens.
• The excimer laser, in contrast, is the “sculptor”: this laser performs the actual refractive correction on the corneal surface or deeper layers, where it reshapes the eye’s refraction by vaporizing tissue bonds.
• The YAG laser is the “gentle splitter” or “plasma vaporizer”: which can open posterior capsular opacification or permanently eliminate disturbing eye floaters inside the eye without external incision.
• The yellow and green lasers are the “welders” and “biostimulators”: responsible for the integrity of the retina, whether securing a tear or initiating the retina’s self-healing processes.

ℹ️ Review our current price list for laser treatments, where you can also find information about the costs of related examinations alongside the fees for individual procedures.

FAQ – Frequently Asked Questions About Laser Eye Surgery