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…
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…
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…
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),…
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…
Holi is a celebration of colour, joy, getting together with family and friends, and food. Everyone in the nation is eager to celebrate Holi with their loved ones now that it is just around the horizon. Holi is a festival…
The keratometer is a specialized instrument used by optometrists and ophthalmologists to measure the curvature of the cornea. This measurement is important because it helps optometrists/ophthalmologists diagnose and manage a variety of eye conditions, such as astigmatism and keratoconus. In…
Steps of the cross-cylinder to Spherocylinder Step 1: Choose either one cross cylinder out of two, as the sphere. Step 2: Subtract the cross-cylinder which was taken as the sphere from the other cylinder which was not taken as the…
Another way of writing lens prescriptions is cross-cylinder form. Usually, this form is never used to write spectacle lens prescriptions. However, it gives you an in-depth understanding of the power of each meridian without the need to add or subtract. …
It’s a method of converting spectacle prescriptions from one cylinder form to another i.e. plus cylinder to minus cylinder or vice-versa Steps of simple transposition: Step 1: Axis change: If the axis of the cylinder is equal or less than…
