12 Uses of Light in Our life| Its Importance and Examples

Light is a form of energy that is visible to the naked eye. It is one of the most important resource for the survival of animals and plants on earth.

The Uses of Light include

ApplicationsDaily LifeHuman Applications
1PhotosynthesisIn medicine
2Vision and sightFor Communication & Signal
3Regulation of body growth, Sleep and Body physiologyElectricity generation
4Drying and evaporationFor Microscopy & spectroscopy
5Sanitation of EarthFor research in physics
6TemperatureFor sterilization

 These bright rays were so fascinating for scientists like Albert Einstein. Because, unlike other energies, it was visible, traveling at great speeds and difficult to explain in scientific terms.

But with improvement in science and technology, light is explored for many benefits and applications as below.

Benefits for Life

1. Photosynthesis for Food formation

The energy from light is trapped as chemical energy and stored as food. As you might have known, this occurs by a process called photosynthesis.

Photosynthesis is a concept in biology wherein food is synthesized in green leaves during the presence of light.

Light is the sole source of food generation for all living organisms on the earth.

Except for a few chemotrophic bacteria? Almost all living beings depend on it for their food and energy.

Plants and other autotrophs synthesize their own food materials by the use of light. The light which falls on the leaves and other greenish surfaces on plants is trapped.

This trapped energy is converted to reserve energy in the form of carbohydrates.

The carbon dioxide and water are used up to form carbohydrates in the presence of sunlight. {CO2 +H2O= C6H12O6}

Uses of Light for plants

Since the plants are the first point of food in the food chain, all the animals obtain their food from these plants.

This phenomenon is observed both on the earth’s surface and also the marine environments.

So, light energy supplies food to all the living beings on the earth.

2. For Vision and sight

All animals, birds can see the objects around them due to the presence of eyes.

But without light, these eyes might be of no use. The eyes receive the reflected images of the objects and send the information to the brain. From this visual information, we comprehend the objects. Hence we can notice that in darkness, we cannot see anything. 

Further, the light is responsible for Colors.

This whole world looks beautiful due to colors. But in darkness, we see no colors. This is because all the colors in this world are possible only due to light.

The beam of light has many spectra. Each spectrum has a color and these are broadly referred to as VIBGYOR.

In full form, it is

  • Violet,
  • Indigo
  • Blue
  • Green
  • Yellow
  • Orange
  • Red

All these colors have different wavelengths and frequencies. And when light falls on an object, it absorbs some spectra and reflects others.

The reflected light falls onto our eyeball and passes the impression to the brain, making it look colorful.

So it is the ability of the object to absorb some spectra of light and reflect the remaining that makes it look colorful.

We would not see the color if the light is absent or our eyes are not functional.

3. Regulation of body growth, Sleep and Body physiology

Exposure to sunlight is essential for life as it helps to produce vitamin D, regulates sleep, helps in body growth and more

For Vitamin D synthesis

for vitamin d synthesis

Vitamin D is a fat-soluble vitamin that is needed for bone health and immunity. This is synthesized in the body under the influence of sunlight. When we expose ourselves, Vitamin D is formed from ergosterol and cholesterol.

When the rays fall on the skin, the ergosterol below the skin converts to vitamin D.

So if someone stays away from sun exposure for long, he tends to develop vitamin D deficiency.

Also, to get a regular dose of vitamin D, it is important to expose to sunlight every day. The best time would be in the mornings and evenings (before dawn).

Sleep-wake cycle and  circadian rhythm

Have you noticed that you tend to fall asleep in the evening without evening knowing it is bedtime? Even you tend to wake up during sunrise without an alarm. This is due to the regulation of the body clock by the light.

Similarly, everyday plants and animals ticking with time due to it.

There is a clock (circadian rhythm) inside both plants and animals, which keeps them active during the day and relaxed at night. This clock is controlled by light.

Plants broaden their leaves during the daytime, starting from sunrise till sunset. Even we can notice leaves and few flowers like sunflower which bent towards the light through the day.

Uses of Light for plant growth

Also, the plants grow in the direction of light as auxin, a plant growth hormone, is regulated by light.

Birds, insects and other animals are also controlled by light. We can notice birds stop making noises in the evening and start making noise early in the morning. This habit is controlled by light as it can tick their body clock. 

This light-dark cycle also influences body growth.

Plants grow towards the sky as they are guided by light. The plant growth hormone, namely Auxin, present in the apical parts (tips) of growing regions, is responsible for it.

Energy For body physiology

As seen before, light energy is stored in food like carbohydrates. These are broken down in the body to produce energy in the form of ATP (adenosine triphosphate). This ATP breaks down to ADP and AMP to release energy in the cells and tissues.

This ATP is utilized for physiological processes like body movements, to build the body proteins, generation of heat in the body, etc.

The cell and nucleus transcription mechanism uses this ATP energy to form messenger RNA (m-RNA).

This m-RNA in the presence of ATP again translates to produce desired hormones, enzymes, proteins and fats required for the body. Thus, the light energy conserved in the food is used up to build and maintain its functions.

4. For Drying and evaporation

Sunlight helps in the drying of the soil, forests, air and rocky surfaces due to its ability to heat up. Also, it helps water evaporate from oceans and water ponds. This drying is helpful in two ways to live on earth like

a) Water cycle:

The water cycle is a way by which freshwater on the earth’s surface is kept recycled for drinking and irrigation. The water from land evaporates to form clouds. These clouds again cause rainfall to return the freshwater to the earth’s surface. So due to rain, there is freshwater to drink and also use for irrigation. Without the water cycle, all the water on the earth would remain in the ocean so that no water is available to drink.

supports water cycle

Or, the water on the earth’s surface would be so filthy such that it is unfit for drinking. So sunlight contributes to the water cycle and thereby maintains rainfall and water for human use.

5. For Sanitation and Scavenging

Sunlight helps in keeping nature clean. Due to drying, there is no growth of weeds, algae and other microbes keeping the environment clean and tidy.

Even dead bodies and other waste material get dried and lose their mass and get degraded fast.

6. Maintenance of temperature

Light energy from the sunlight raises the temperature on the earth. Due to this, life exists on earth.

If you think why? Just imagine those areas of the earth without proper sun exposure in the whole year.

Those areas are icy and even have heavy snowfall. If the sunlight is absent, the temperature of the earth can drop drastically such that the whole water on the earth gets frozen.

If this happens, the animals, especially homeotherms, die instantly due to low temperatures. Even the poikilothermic animals may find it difficult to survive. So light is essential to maintain temperature on the earth and thereby life.

Human Applications of this energy

1. In medicine

In medicine, it is widely used as phototherapy. Exposure to light is preferred in the treatment of newborn jaundice, skin conditions like psoriasis, mood disorders and a certain type of cancers.

2. For Communication

Data transmission

Light is used to transmit data through optic fibers. Since it travels very fast, this technology is preferred for data transmission. 

It is used for broadcasting, telephone calls, computer networking, medical diagnosis. 

Signal system

Light is the crucial visible signal. We use it as traffic signals, navigation signals, etc.

Even our TV remotes use infrared rays to give the signal to Television.

Thus light appears to be a simple phenomenon of the universe that has diverse uses to humans and life on earth.

3. Electricity generation

Solar energy: Rays from the sun help to generate green energy or renewable energy.

Solar panels imbibe sun rays and convert them into electric energy, which can be used for domestic needs.

Now we have realized the importance of solar energy. It is one of the alternative energy or renewable energy which is safe for the environment. It generates no pollution and other harmful wastes.

for generation of electricity with solar plates

Other means of energy generation by the use of coal and atomic energy are responsible for global warming.

So if we shift towards this form of energy, we will be saving the environment.

4. For Microscopy & spectroscopy


It is a technique used to observe minute objects invisible to the naked eye by the use of a microscope. This technique needs light to help observe the image clearly under the lens.

The microscope is also used to study microorganisms, diagnose diseases like by use of blood, sputum samples.


Light is used for the analysis of compounds by spectrophotometry. This spectroscopy can be used for both qualitative and quantitative analysis. There are many forms of spectroscopy that vary based on the spectra and wavelength of light used.

Some of them include colorimetry, atomic absorption spectroscopy. This spectroscopy is further extended to be combined with other analytical techniques like chromatography.

5. For research in physics

Light is widely used to study the properties of radiation. It is also used to study its properties and interaction with matter as a part of optical physics. 

Light is also essential to observe objects in-universe by the Astronomers.

6. For Sterilization

Light, especially its ultraviolet component, is an excellent sterilizing agent. Haven’t you noticed in a supermarket or hospital the use of UV lamps? These UV lamps are good sterilizers. The UV rays kill the microbes in the air keeping the area sterile. So UV light is classified under the dry method of sterilization.

Sunlight is an effective sterilizing agent. When blankets and other hospital mattresses are dried in sunlight, all the microbes get killed and are relieved of bad odor.


19 thoughts on “12 Uses of Light in Our life| Its Importance and Examples”

  1. The speed of Light travel is very much greater than the speed of the sound.Hence, we see light first during lightening as it travels fast to our eyes. While, the sound travels slower and we hear it latter.

  2. Very informative for use in my Bible study of, “You are the light of the world.” I had to list all the benefits and effects of light.

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