Waves are disturbances that transfer energy from one place to another without moving matter permanently. They can be mechanical (like sound or water waves) needing a medium, or electromagnetic (like light), which can travel through empty space.

1. What is
Visible Light?

2. In the 1660s, Isaac
Newton discovered
that sunlight is
made up of
different colors.
Through a small opening in his
room, he allowed sunlight to pass
through a glass prism.

3. Humans can see colors because of
the presence of cone cells in the
eyes.
The human eye has around 6 to 7
million cone cells.
What is visible
to the human
eye?

4. How the
Eye

5. Why is it Important?
Helps us interpret the world around us.
Essential for art, design, safety, and daily
life.
What is Color
Perception?
The ability of the human eye to distinguish different
wavelengths of light as colors. A complex process involving the
eyes, brain, and light.

6. Color
and
Light
Objects absorb and reflect specific
wavelengths.
The reflected wavelengths determine
the color we perceive.
Light and
Wavelengths
Visible light is part of the
electromagnetic spectrum.
Wavelengths range from ~380 nm
(violet) to ~750 nm (red).

7. Cornea
• It acts as the eye’s first lens, bending
(refracting) incoming light to help focus
it onto the retina.
Lens
• It fine-tunes the focus of light onto the retina by
changing its shape, a process called
accommodation.
Key Structures
Involved in Color
Perception
LENS
CORNEA

8. Key Structures Involved in Color
Perception
RODS
Rods are photoreceptor cells
responsible for scotopic vision (vision
in low-light conditions).
They are highly sensitive to light and
allow us to see in dim environments,
such as at night.
Detecting Light Intensity
CONES
Cones are photoreceptor cells
responsible for photopic vision
(vision in bright light).
They detect color and provide high-
resolution, detailed vision.
Detecting Color

9. S-Cones (Short Wavelength)
Sensitive to short wavelengths (blue).
Peak sensitivity around 420-440 nm.
Three
Types of
Cones
M-Cones (Medium
Wavelength)
Sensitive to medium wavelengths (green).
Peak sensitivity around 530-540 nm.
L-Cones (Long Wavelength)
Sensitive to long wavelengths (red).
peak sensitivity around 560-580 nm

10. Yellow light
Stimulates both L-cones (red) and M-cones
(green), but not S-cones (blue).
White light
Stimulates all three cone types equally.
These cones work together to detect and
differentiate colors.
Each cone type responds to a range of
wavelengths, not just one specific color.
How Cones
Work
Together

11. A deficiency in one or more types of cones. Most
common type: red-green color blindness.
What is Color
Blindness?
Causes
• Genetic factors.
• Damage to the retina or optic nerve.
Impact
• Difficulty distinguishing
certain colors.
• Does not mean seeing in black
and white.

12. Animals See Differently
• Some animals (e.g., bees) can see
ultraviolet light.
• Dogs have fewer cones and see fewer
colors than humans.
Fun Facts
About
Color
Perception
Cultural Differences
• Some cultures have more words for specific
colors.
• Language can influence how we perceive
colors.

13. GAMMA
RADIO
WAVES
MICRO-
WAVES
INFRARED X-RAYS
ULTRA-
VIOLET
10
2
10
-12
1
10
1
10
-1
10
-2
10
-3
10
-4
10
-5
10
-11
10
-10
10
-9
10
-8
10
-7
10
-6
NAME OF
WAVE
WAVELENGTH
(METERS)
a narrow portion of the
electromagnetic spectrum
that humans can see
Its frequency falls between 400 to 750
terahertz (THz).
Its wavelength ranges between
400-700 nanometers.
FREQUENCY WAVELENGT
H
VISIBLE
LIGHT
VISIBLE
LIGHT

14. What happens
if sunlight is
allowed to pass
through a glass
prism?
?
?

15. The visible light spectrum is composed of all the rainbow colors. Each color corresponds to a specific
wavelength.
violet (shortest
wavelength)
red (longest
wavelength)
LIGHT AND
COLOR

16. Visible light is also
used to transmit
high-speed data.
Endoscopes use
fiber optics to allow
doctors to see
internal organs and
vessels.
Humans see
objects in the
visible light
spectrum.
Applications of Visible Light
VISION MEDICINE COMMUNICA
TIONS