Properties of Ophthalmic lens

Properties of ophthalmic lens ppt

Optical properties: The optical properties of ophthalmic lenses encompass their unique characteristics that enable them to accurately refract and focus light, resulting in clear and precise vision. Mechanical properties: The mechanical properties of ophthalmic lenses encompass their physical attributes, including durability, flexibility, and resistance to impact or breakage, ensuring they can withstand everyday use and … Read more

Aberration in Ophthalmic lenses

Aberration in Ophthalmic lenses

Aberration refers to the inability of a lens to create a perfect image of an object, resulting in imperfections in the formation of images within an optical system.

Types of Bifocal lens

Types of bifocal lens ppt

When a patient needs separate vision correction for both distance and near vision, they can opt for lenses that integrate these corrections into two distinct areas on each lens. Each area possesses its own focal properties tailored for specific distances. Bifocals, as their name implies, consist of two distinct lenses with different focal points, accommodating … Read more

Progressive Addition Lenses

Progressive addition lens ppt

Progressive addition lenses are single-piece lenses that feature a smooth transition in curvature across the lens surface. The curvature gradually increases from the upper distance portion to the lower near portion. Unlike bifocal or trifocal lenses, progressive lenses offer a seamless solution for individuals with presbyopia, providing optimal dioptric power for all distances. This ensures … Read more

AC/A ratio (Accommodative convergence/ Accommodation ratio)

AC/A ratio Calculated heterophoria method

Accommodative convergence/ Accommodation ratio also known as AC/A ratio, is a measurement of changes in accommodative convergence in prism diopters induced when the patient exert or relax 1 diopter of accommodation. Changes in the accommodation are either evoked by placing plus lens which relaxes accommodation or by minus which activate accommodation or when a person … Read more