For Shaima’a Mohammed Mohi The optical tweezers technique has been proved to be a powerful microscopy instrument able not only for manipulating the biological particles but also of measuring important biophysical and mechanical properties. Optical tweezers is based on focusing laser beam by a high numerical aperture objective lens. In this work, two-channel laser tweezers technique was proposed to trap RBCs. The first cannel technique is based on single and/or dual-laser beams for investigating the optical deformability. The other one is dual-mode polarized single-laser based on different polarization states for studying the optical folding and rotation of single RBCs. In this experimental study, the RBCs mechanical properties are measured in patients with (SCA)   and follow-up  same patients on regular and restricted use of HU after three months for comparison,  as well as  control group with matched age and gender