Topographic characterization of unworn contact lenses assessed by atomic force microscopy and wavelet transform
Ştefan Ţălu1, Krzysztof StȨpień2, Mustafa Oguzhan Caglayan3
1Faculty of Mechanical Engineering, Department of AET, Discipline of Descriptive Geometry and Engineering Graphics, Technical University of Cluj-Napoca, 103-105 B-Dul Muncii St., Cluj-Napoca 400641, Cluj, Romania.
Abstract:
This paper analyses the three-dimensional (3-D) surface morphology of optic surface of unworn contact lenses (CLs) using atomic force microscopy (AFM) and wavelet transform. Refractive powers of all lens samples were 2.50 diopters. Topographic images were acquired in contact mode in air-conditioned medium (35% RH, 23°C). Topographic measurements were taken over a 5 µm × 5 µm area with 512 pixel resolution. Resonance frequency of the tip was 65 kHz. The 3-D surface morphology of CL unworn samples revealed (3-D) micro-textured surfaces that can be analyzed using (AFM) and wavelet transform. AFM and wavelet transform are accurate and sensitive tools that may assist CL manufacturers in developing CLs with optimal surface characteristics.
