How the Eye Takes in Light
Human eyes detect both intensity and wavelength of light with wavelengths in the 390- to 740-nanometer range. The eyes take in light through the cornea and lens at the front of the eye and focus it to form an image. Does this Spark an idea?
-
Features
-
The eye is surrounded by a tough layer of connective tissue called the sclera. The portion of the sclera in front of the eye is transparent and is called the cornea, which encloses a fluid called the aqueous humor. Behind the aqueous humor lies the lens, and behind the lens is a jelly-like fluid called the vitreous humor.
Function
-
Both the cornea and the lens refract or bend incoming rays of light to form an image on the retina. Although the cornea does much of the refraction, the lens, unlike the cornea, is adjustable, so it's what your eyes use to focus. Your eyes adjust the thickness of the lens using the ciliary muscles and suspensory ligaments.
-
Fun Fact
-
The speed of light in a given material is equal to its frequency times the wavelength. When photons of light travel through a material like water, they travel more slowly than they would in air. The frequency remains unchanged, so the wavelength must decrease. This shift in wavelength doesn't change the colors you see if you go underwater; however, all that matters as far as your color perception is concerned is the wavelength of the light inside the vitreous humor of your eye.
-
References
- Photo Credit Jupiterimages/Goodshoot/Getty Images
