Roving Ring Scotoma
Aphakia is defined as the absence of a natural crystalline lens from the eye, due to any cause. Causes include congenital aphakia, surgical aphakia, traumatic extrusion of the lens, and…
Gross anatomy of the Extraocular Muscles
The extraocular muscles are a group of six muscles located around the eye, working in perfect harmony to control its movement. These muscles are named based on their location and…
Seeing in High Definition: The Marvels of Contrast Sensitivity
Contrast sensitivity is a critical aspect of visual function that is often overlooked compared to other visual parameters, such as visual acuity. However, it plays a vital role in our…
PRINCIPLE OF LENSOMETER
Lensometry is an ophthalmic procedure that helps a clinician to either to assess the: Spherical power. Cylinder power. Cylinder axis. Optical center. Prism reference point. Adds in bi-, tri- and…
Abnormal retinal correspondence
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…
CHILDHOOD BLINDNESS
A blind child is an individual aged <16 years, who has a visual acuity in the better eye of <3/60. Childhood blindness is an important public health problem in developing…
NPCB & VI
India was the first country in the world to launch the 'National Programme for Control of Blindness (NPCB)' in year 1976 as 100% centrally sponsored programme with the following goals:…
EYE BANKING
Eye bank is an organization which deals with the collectin, storage and distribution of cornea for the purpose of corneal grifting, research and supply of the eye tissue for other…
Non – Optical Devices for Low Vision
Types of non- optical devices Relative size and larger assistive devices Glare, contrast, and lighting control device Posture and comfort maintenance device Handwriting and written communication devices Medical management devices…
SUPERIOR OBLIQUE MUSCLE OVERACTION
A bilateral lesion that injures both anterior canal pathways or disinhibits both posterior canal pathways will increase prenuclear innervation to the superior oblique and inferior rectus subnuclei, resulting in a…