Ocular Anatomy and Conditions Flashcards
7 cards from real ABO NOCE Basic Opticianry practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Ocular Anatomy and Conditions flashcards as text
The optic nerve exits the eye at a point called the:
Answer: Optic disc
The optic disc (blind spot) is where the optic nerve fibers converge and exit the eye, containing no photoreceptors.
Which photoreceptors are primarily responsible for color vision?
Answer: Cones
Cones are concentrated in the macula and fovea and contain photopigments sensitive to red, green, and blue light for color discrimination.
The cornea receives its nutrients primarily from which source?
Answer: Aqueous humor and tears
The avascular cornea relies on aqueous humor for posterior nutrition and the tear film and limbal vessels for anterior nutrition.
Which condition involves the lens of the eye becoming progressively opaque?
Answer: Cataract
A cataract is a clouding of the crystalline lens that reduces light transmission and causes blurred, hazy vision.
The sclera transitions to the cornea at a boundary zone known as the:
Answer: Limbus
The limbus is the transitional zone between the opaque sclera and transparent cornea and also contains stem cells for corneal regeneration.
Astigmatism is most commonly caused by irregular curvature of which structure?
Answer: Cornea
Most astigmatism (corneal astigmatism) results from the cornea having different curvature radii in different meridians, preventing a single focal point.
Which layer of the retina converts light energy into electrical signals?
Answer: Photoreceptor layer
The photoreceptor layer, containing rods and cones, performs phototransduction — converting light into neural signals.