Editing LASIK (section)

=== Contraindications ===
Not everyone is eligible to receive LASIK. Severe [[keratoconus]] or thin corneas may disqualify patients from LASIK, though other procedures may be viable options. Those with [[Fuchs' dystrophy|Fuchs' corneal endothelial dystrophy]], corneal epithelial basement membrane dystrophy, [[Retinal detachment|retinal tears]], autoimmune diseases, [[Dry eye syndrome|severe dry eyes]], and significant [[blepharitis]] should be treated before consideration for LASIK. Women who are pregnant or nursing are generally not eligible to undergo LASIK.<ref>{{Cite web |title=LASIK for Myopia and Astigmatism: Safety and Efficacy – EyeWiki |url=https://eyewiki.aao.org/LASIK_for_Myopia_and_Astigmatism:_Safety_and_Efficacy#LASIK_Complications |access-date=6 August 2019 |website=eyewiki.aao.org |archive-date=14 September 2024 |archive-url=https://web.archive.org/web/20240914194642/https://eyewiki.org/LASIK_for_Myopia_and_Astigmatism:_Safety_and_Efficacy#LASIK_Complications |url-status=live }}</ref>

People with large pupils (e.g. due to taking medications or in the younger age group) may be particularly prone to symptoms such as glare, halos, starbursts, and ghost images (double vision) in dim light after surgery. Because the laser can only work on the inner section of the cornea, the outer rim is left unaffected. In dim lighting, a patient's pupils dilate and may be predisposed to optic aberrations due to refractive asynchrony of the two regions with regards to the incoming light.<ref name="FDA L"/>