Week 1 The Eye Flashcards
What is light in terms of its physical nature?
Light is electromagnetic radiation, traveling in waves at the speed of 299,792,458 m/sec. It consists of photos, with amplitude determining intensity, and wavelength and frequency defining other properties
What is the range of visible light on the electromagnetic spectrum?
visible light ranges from 380 to 760 nm
What is the function of the cornea?
The cornea is the transparent outer coating of the eye that serves as the principle means of focusing light
What is the role of the pupil
The pupil is the circular hole in the center of the iris that allows light to enter the eye
What is the lens function in the eye
The lens focuses images onto the retina by adjusting its shape for different distances, a process known as as accommodation
What is phototransduction
It is the process by which the photoreceptors in the retina convert energy into electrochemical energy - neural impulses
What are the two types of photoreceptors and their role
Rods: responsible for vision in low light conditions and sensitive to darkness
Cones: responsible for bright light vision, color vision, and detecting fine details
How are rods and cones distributed in the retina
There are about 6 million cones and 120 million rods. The fovea contains only cones, while the peripheral retina has both rods and cones
What causes the blind spot in vision
The blind spot is the point where the optic nerve exits the retina, which has no photoreceptors
Why don’t we notice the blind spot in everyday vision
The blind spot is located in the peripheral visual field and the brain compensates for it by “filling in” the missing information
What happens when light hits the photopigment molecule
The photopigment molecule splits, activating the photoreceptors and initiating phototranduction, where light is converted into a neural signla
What is the role of retinal ganglion cells
Retinal ganglion cells summarize input from photoreceptors and carry the neural signal from the eye to the brain via their axons
