Am I a Good Candidate for FLAAK? Pre-Screening Criteria Explained By Kaşkaloğlu Eye Hospital | İzmir, Turkey You’ve researched the FLAAK procedure. You understand how it works. You’ve looked at before and after photos and imagined what a different eye color might look like on you. But one important question remains before anything else: Are you actually a suitable candidate? This is the most important question in the entire process — and it is one that no website, simulator, or social media post can answer for you definitively. Only a thorough pre-operative examination by an experienced ophthalmic surgeon can do that. What this article can do is explain the key criteria we assess at Kaşkaloğlu Eye Hospital, what typically makes someone a good candidate, and what factors may require extra evaluation or rule someone out entirely. Reading this before your consultation will help you arrive informed, ask better questions, and have realistic expectations. Why Candidate Selection Matters So Much FLAAK keratopigmentation is a safe, minimally invasive procedure when performed on the right patient with the right pre-operative assessment. The femtosecond laser creates a precise micro-tunnel in the corneal stroma, and biocompatible pigment is placed within it. The cornea remains intact; the internal structures of the eye are never touched. But the cornea is not the same in every person. Its thickness, curvature, hydration, cell density, and structural integrity all vary. A cornea that is too thin, structurally irregular, or affected by certain conditions is not an appropriate candidate for the procedure — not because the technology fails, but because surgery on a compromised cornea carries risks that the procedure is not designed to take on. This is why our pre-operative screening is comprehensive and non-negotiable. It protects you. General Eligibility: The Basics Before the detailed clinical assessment, there are some broad criteria that apply to almost all candidates: Age: Candidates should be at least 18 years old. We prefer that patients are in their twenties or older, as the eye continues to develop through the late teenage years. There is no strict upper age limit, but overall ocular health becomes more relevant with age. Stable general health: Candidates should be in good general health and free from active systemic diseases that could impair healing or increase surgical risk. Conditions such as uncontrolled diabetes, autoimmune diseases, or conditions that affect the immune system require careful evaluation and, in some cases, may rule out the procedure. Realistic expectations: A candidate must understand what FLAAK can and cannot achieve. It permanently changes the apparent color of the eye by masking the iris with pigment placed in the cornea. The result is a natural-looking color change — not a theatrical transformation. The final color depends on your starting eye color, your skin tone, and the pigment selected in consultation with your surgeon. FLAAK does not correct vision, does not treat eye disease, and does not produce the same result in every person. Motivation: Candidates should want the procedure for themselves — not under pressure from others. This is an elective, permanent change. We take time in our consultations to ensure that patients have considered the decision carefully. The Clinical Assessment: What We Examine Every candidate undergoes a comprehensive pre-operative examination at Kaşkaloğlu Eye Hospital. We use three advanced diagnostic systems — the Zeiss VisuMax 800, the Pentacam HR, and the iTrace Visual Analyzer — to build a precise picture of each patient’s ocular anatomy. Here is what we are looking for: Corneal Thickness This is one of the most critical measurements. The FLAAK procedure creates a micro-tunnel within the corneal stroma — the middle layer of the cornea. To do this safely, the cornea must have sufficient thickness to accommodate the tunnel while leaving adequate tissue above and below it. Corneal thickness varies naturally from person to person. Most people have adequate thickness for the procedure. However, patients with thinner-than-average corneas may not be suitable, and this can only be determined through accurate measurement with instruments like the Pentacam HR, which provides a detailed three-dimensional map of the entire cornea. Corneal Shape and Regularity We assess the curvature and regularity of the cornea across its entire surface. Patients with keratoconus — a condition where the cornea progressively thins and bulges into a cone shape — are generally not suitable candidates for FLAAK. This is a firm contraindication, even in early or mild cases, because operating on a structurally compromised cornea is unsafe. Similarly, patients with other corneal ectasias or significant irregular astigmatism require careful individual assessment. Corneal Endothelial Cell Density The endothelium is the innermost layer of the cornea — a single layer of cells responsible for keeping the cornea clear by pumping fluid out of the tissue. These cells do not regenerate. If their density is too low, the cornea’s ability to maintain its clarity is compromised. We measure endothelial cell count as part of our pre-operative screening. Patients with significantly reduced endothelial cell density may not be suitable for the procedure. Intraocular Pressure Elevated intraocular pressure (IOP) is a key indicator of glaucoma — a serious eye condition involving damage to the optic nerve. Patients with glaucoma or ocular hypertension require careful evaluation. In many cases, well-controlled, stable glaucoma is not an automatic disqualification, but it requires discussion with your surgeon about the specific risks and benefits in your individual case. History of Previous Eye Surgery Many patients who have had previous refractive surgery — such as LASIK, PRK, or SMILE — can still be candidates for FLAAK, but this requires individual assessment. Previous surgery alters the cornea’s thickness and structural properties. Our diagnostic systems can evaluate whether sufficient corneal integrity remains for the FLAAK procedure to be performed safely. Patients who have had corneal transplants are generally not suitable candidates. Active Ocular Disease or Infection Any active infection, inflammation, or disease affecting the eye at the time of evaluation will need to be resolved before the procedure can be considered. This includes conditions such as active uveitis, dry eye disease