Refraction through spherical lenses
Lens: A piece of transparent material (such as glass) whose two opposite regular surfaces are either curved or one is curved and the other is flat and which is used…
Lens: A piece of transparent material (such as glass) whose two opposite regular surfaces are either curved or one is curved and the other is flat and which is used…
Anti reflection coatings minimize the reflection of one or many wavelengths and are typically used on the surface of lenses so that less light is lost. A simple coating can…
Spherical aberration is an optical aberration that occurs when all incoming light rays after passing through spherical surface end up focusing at different points . Lights rays that strike a…
Keratometry is a simple, rapid and non-invasive test. It has some limitations. It measures the curvature of the anterior corneal surface usually across a fixed chord length of 2 to…
Aspheric lenses have non-spherical shapes, and have a more complex front surface, such as ellips, parabola, hyberbola, as well as toric which resembles a section of the surface of a…
In a state of normal binocular single vision, there exists a precise physiological relationship between the corresponding points of the two retina. Thus, the foveae of two eyes act as…
Presbyopia affects 1.8 billion people worldwide, according to the World Health Organization (WHO). The American Academy of Ophthalmology (AAO) describes it as a common age-related decline in the eye’s near…
Quality of life (QOL) is known to be an important construct, particularly in relation to chronic diseases. It can be assessed by measuring the degree of impairment experienced in activities…
A person with low vision is one who has impairment of visual functioning even after treatment and/or standard refractive correction, and has a visual acuity of less than 6/18 to…
There are many low vision devices to help with daily activities. Talk with your vision rehabilitation team about solutions for your specific needs. Also ask if you will need training…
Vision rehabilitation (often called vision rehab) is a term for a medical rehabilitation to improve vision or low vision. In other words, it is the process of restoring functional ability and…