This lecture covers the concept of magnification in microscopy, focusing on the human eye as a single lens system and the limitations of optical systems. It explains how the human eye accommodates and its specifications, such as angular and spatial resolution. The lecture also discusses magnification with a magnifying glass and a compound microscope, detailing the role of objective and eyepiece lenses in image formation. It concludes with the finite correction in compound microscopes and the standard tube length distance between objective and eyepiece.