CLT Photobiology & Light Science 2

Question 1

What is irradiance in the context of light therapy?

Accepted Answer

Power per unit area (mW/cm²)

Answer

Irradiance, measured in milliwatts per square centimeter (mW/cm²), describes the power of light delivered to a surface area at any given moment.

Question 2

What phenomenon occurs when light passes from air into tissue and changes direction?

Accepted Answer

Refraction

Answer

Refraction occurs when light changes speed and bends at the boundary between two media with different refractive indices, such as air and skin.

Question 3

Which wavelength range penetrates the deepest into human tissue?

Accepted Answer

Near-infrared (700–1100 nm)

Answer

Near-infrared wavelengths (700–1100 nm) penetrate the deepest into tissue because they are least scattered and absorbed by superficial chromophores.

Question 4

What is a chromophore in photobiology?

Accepted Answer

A molecule that absorbs specific wavelengths of light

Answer

A chromophore is a molecule capable of absorbing specific wavelengths of light, triggering photochemical or photobiological reactions.

Question 5

The Beer-Lambert Law is used in light therapy to describe which relationship?

Accepted Answer

How light absorption increases with chromophore concentration and path length

Answer

The Beer-Lambert Law states that light absorption is proportional to the concentration of the absorbing substance and the path length through which light travels.

CLT - Certified Light Therapist Practice Test

CLT - Certified Light Therapist Practice Test

CLT Photobiology & Light Science 2