Worth four dot test

worth 4 dot test

Worth four dot test is a subjective procedure test to evaluate the presence of fusion, suppression, diplopia and abnormal retinal correspondence. The test can be performed for both distance and near Procedure: Ask the patient these questions Interpretation All below mentioned interpretation is for eyes when red glass is in front of the patient’s right … Read more

BRUCKNER TEST (FUNDUS RED REFLEX TEST)

Bruckner test

The Bruckner test is a simple yet very useful objective assessment for diagnosing abnormalities of the eye and refractive errors. The ophthalmoscope light is shone onto the eye and the light reflected from the fundus is observed. The interpretation of the finding is based on the position of the corneal light reflex and the colour … Read more

Prentice’s Rule

Prentice's rule

Prism power Prism power is the amount of light displaced in centimetres at a distance of 1m away from the prism or lens. Prism power is denoted by Δ Δ = Image displacement in centimetre / 1 Meter Suppose a plus lens is decentred downward. The parallel ray instead of passing through the optical centre … Read more

The protective mechanism in the Eye

eye protective mechanism

Many mechanisms exist to protect the eye from external injury. Mechanism of potential damages to the eye can ocular as: 1.Protection from mechanical damage The orbit: The eyelids: The corneoscleral shell 2.Protection from chemical damage Eyelid closure Bell’s phenomenon Tears Corneal epithelial barrier 3.Protection from biological damage Tear film and conjunctiva: Corneal epithelium and Bowman’s … Read more

Compounding and resolving prism

Compounding and resolving prism

Introduction In a few cases of prism prescriptions, where both horizontal and vertical prisms are required to correct the deviation. In such a case, one single prism can be computed in the manufacturing process to have the exact same result as the combination of the two specified prisms. Compounding prism Compounding prism refers to the technique … Read more

Prism orientation notation

Prism 360 and 180 Notations

Prism orientation Unlike cylindrical lenses where the axis of cylindrical lenses is noted from 0 to 180, prisms have a base direction throughout 360 degrees. Whereas, a cylindrical lens axis of 90 degrees is similar to 270 degrees but in the case of a prism if the base orientation is toward 90 degrees it is … Read more

Prisms

Prism introduction

Prisms are wedge-shaped lenses that divert light towards their bases without altering their vergence. An optical prism is a transparent solid device that bends light. It is often composed of glass or plastic. It has two flat surfaces that are usually inclined with one another, as well as a surface that isn’t parallel. A prism can … Read more

CATARACT SCREENING IN INDIAN VILLAGES

Cataract screening

Cataract is one of the major eye health disorders in the World leading to blindness and India is no exception to it. According to NPCB, Cataract alone is responsible for 62.6% of blindness among the Indian population. Cataract comes under avoidable blindness, which can be successfully treated with a surgery. The lack of basic eye … Read more

Beauty and Safety: The Essential Guide to Eye Cosmetics and Ocular Health

Eye makeup and Eye health

Eye cosmetics are meant to enhance the appearance of the eye thus making it more attractive. It is believed that it boosts the confidence level of people. Currently available eye cosmetics in the market include liquid eyeliner, pencil eyeliner (Kajal), eyeshadow, glitters, eyebrow pencil, artificial eyelashes with glue, mascara, concealer, etc. Eye cosmetics are used … Read more

Toric transposition

Front and back surface of toric lens

What is a Toric lens? A toric lens is defined as a lens which has one surface toroidal (one of the principal meridians is more curved than the other principal meridian) and another surface of the lens is spherical (convex or concave). What is Toric transposition? It is a method which enables, the Toric lens … Read more