Optics and Refraction — Flashcards

Flashcard 31: In _____-the-rule astigmatism, the curvature of the vertical meridian is more than the horizontal meridian

Answer: with

Flashcard 32: Angle _____ is the angle between the line of sight and pupillary axis at the cornea

Answer: lambda

Flashcard 33: _____ blindness is vision 1/60 to just perception of light

Answer: Manifest

Flashcard 34: The _____ surface of the cornea is the most important factor influencing the focus of light rays on the retina.

Answer: anterior

Flashcard 35: A condensing lens is needed in _____ ophthalmoscopy, usually of 20 D

Answer: indirect

Flashcard 36: In fundoscopy, more the power of condensing lens, _____ the magnification and more the field of view

Answer: less

Flashcard 37: Hruby lens provides a _____ field of vision with high magnification

Answer: small

Extra: Hruby lens is a -58.6 D plano-concave lens used for slit-lamp biomicroscopy. It provides an erect, virtual image with high magnification and a small field of view (approx. 5-8°).

Flashcard 38: The _____ effect refers to the greater sensitivity of the retina to perpendicular rays than the oblique rays

Answer: Stiles Crawford

Flashcard 39: High refractive index of the _____ of the lens than that of the peripheral cortex is one of the natural mechanisms to decrease aberration of the eye

Answer: core of the nucleus

Flashcard 40: Purkinje image 4 is formed from the _____ surface of the lens and is inverted

Answer: posterior