# Laser Processing of Intraocular Lenses
###### Abstract
Another reason is that commercially available IOLs vary in terms of materials (PMMA, silicone, acrylic, hydrophobic acrylic, etc.) and can have very different characteristics and polymer compositions, not always publicly disclosed, making very difficult if not impossible the standardization of the IOL study under various laser processing studies. Therefore, there is a clear need for further studies with new micromachining approaches as there is a considerable gap and a long way to the successful laser-based customization of IOLs. Laser technology has been widely utilized in various technological, industrial, and medical fields for material processing purposes over the course of many years [14; 15; 16; 17]. It finds applications in ablating, drilling, cutting, and other material modifications achieved by focusing concentrated laser energy onto the target material. The advantages of laser processing, such as reduced heat-affected zones, speed, versatility, and environmental considerations, make it stand out among alternative methods as it also provides rapid prototyping and customizable solutions. The available lasers cover a spectrum of pulse durations, from continuous wave (CW) operation to nanosecond (ns), picosecond (ps), and femtosecond (fs) pulses, and also at various wavelengths from ultraviolet to the infrared band. Many studies have been performed into the physics of ultrashort pulse laser-matter interaction, emphasizing the differences in ablation mechanisms between short and ultrashort pulses [18; 19; 20; 21]. The utilization of laser ablation by femtosecond lasers has been previously studied as an approach for patterning and shaping IOLs [22; 23; 24]. The primary goal was to provide ophthalmologists with a tool for tailoring IOL patterns to suit the specific needs of individual patients using laser technology. In this work, the laser ablation process was employed to create processed areas on the curved surface of commercially available IOLs. Two types of IOLs were considered: non-flexible PMMA lenses and flexible acrylic lenses. The primary objective is to produce the uniform and consistent modification of the IOL's surface. By creating a homogeneous processed area, the IOLs are more likely to exhibit consistent optical properties and char acteristics, which is important for achieving predictable and reliable visual functionality for patients who undergo cataract surgery and have these IOLs implanted. We employed three types of lasers, a femtosecond laser, a nanosecond laser, and a continuous wave diode laser, with very different characteristics, covering a wide range of laser sources in this study. Specifically, the femtosecond laser system emitted 370 fs pulses and operated at a wavelength of 1064 nm. The nanosecond laser system operated at 355 nm with a 5 ns pulse duration. The CW diode laser operated at a wavelength of 405 nm. Firstly, ablated areas were systematically produced on the surface of both IOLs using the femtosecond laser. Additionally, a detailed study was conducted to determine the optimal laser parameters for producing spot patterns with desired characteristics, involving both the CW diode and nanosecond laser. Overall, the experiments aimed at understanding the effects of the laser ablation of various types of lasers on different IOLs and to optimize the laser parameters for achieving uniform and consistent modifications on the IOL surfaces, thus identifying suitable laser patterning approaches potentially compatible with highly accurate IOL modification needed. This study was also supported with Raman spectroscopy for the identification of possible alterations of optical and structural properties of laser-processed IOLs, which is an important element for their usability.