الفهرس 
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Abstract
Laser-Assisted in Situ Keratomileusis (Lasik) is a very common vision correction technique. It is widely utilized for handling disorders like myopia, hyperopia and astigmatism Among different complicated optical elements of the eye, the cornea represents more than 65٪ of the focusing power. LASIK surgery is performed through two main steps; first: creation of a flap in the cornea via a surgical tool called microkeratome or with a femtosecond laser, second: removing some corneal tissue based on the excimer laser ablation effect Excimer laser at 193-nm is the most common type of laser used to reshape the cornea, however, it has many disadvantages including the high price and toxicity of its active medium. Moreover, the laser itself is aggressive to the optics high electric field to pump the medium that is noisy and not suitable for pacemaker patients. So, the question is: Can we propose any alternative to such type of laser? The proposed work is arranged in two sections simulation and experimental. We studied the thermal effect of the 193nm with comparison to other UV wavelengths (210, 213, 223, 248 and 266 nm) with same parameters also different devices (Zeiss Mel 90, PulzarTM Z1, katana laser soft, Technolas Teneo317, Alcon EX500 and MedilexTM) with different wavelengths and different laser parameters compared using COSMOL multiphysics and MATLAB software programs as a stimulation section. In the experimental section, we studied the photo-ablation of a developed 266-nm laser generated from the second harmonic Nd:YAG laser to inspect its efficacy as an alternative to the common 193-nm. Moreover the photo-ablation effect was examined on cornel tissue simulating phantoms ”Poly methyl methacrylate (PMMA) and ex-vivo rabbit corneas. Results of the stimulation section revealed that, the minimum temperature recorded was 68.6°C for 266-nm, while regarding the devices comparison, Katana laser soft showed minimum temperature 45.8°C as a flying spot device and MedilexTM as a board beam showed minimum temperature 30.5°C at 248-nm. Results of the experimental work showed good ablation effect of the produced 266- nm with a stable pulse energy in the PMMA while in the ex-vivo rabbit cornea histology showed collateral damage, minimal thermal damage and relatively smooth ablation surfaces at targeted regions sides with no signs of edema or distortion of the adjacent corneal stroma have been observed. These results provide a promising alternative to the 193-nm excimer laser for corneal ablation process.