CHAPTER I

INTRODUCTION

Background of the Study

In recent years, the rapid development of digital technology has revolutionized how individuals

learn, communicate, and entertain themselves. Smartphones, tablets, laptops, and desktop

computers have become indispensable tools, particularly among adolescents. For senior high

school students, these devices are not merely for leisure but also essential for academic purposes,

such as conducting research, attending online classes, and completing school-related tasks.

However, the frequent and prolonged use of electronic devices also brings unintended health

consequences. A growing body of research highlights that the blue light emitted by screens plays

a significant role in disrupting circadian rhythms, delaying the production of melatonin, and

reducing sleep quality. Sleep is a fundamental biological process that contributes to memory

consolidation, emotional regulation, physical growth, and cognitive performance. Adolescents,

including senior high school students, require 8–10 hours of sleep per night to function

optimally. Unfortunately, evidence suggests that many students are not meeting this requirement

due to excessive screen time before bedtime.

Poor sleep quality among adolescents is associated with fatigue, irritability, weakened immune

system, poor academic performance, and even long-term health risks such as obesity and

cardiovascular disease. Despite these risks, the use of electronic devices at night continues to

rise, with students spending multiple hours scrolling on social media, playing online games, or

streaming videos before falling asleep.

This research, therefore, investigates the relationship between blue light exposure from

gadgets and the sleep quality of senior high school students. Understanding this relationship

is crucial in promoting healthier lifestyle practices and ensuring that students maximize both

their academic potential and overall well-being.

Statement of the Problem

This study aims to examine the effect of blue light exposure on the sleep quality of senior high

school students. Specifically, it seeks to answer the following questions:

1. How much time do senior high school students spend using gadgets before bedtime?

2. What is the level of sleep quality of senior high school students in terms of:

a. Sleep duration

b. Sleep onset latency (time taken to fall asleep)

c. Sleep satisfaction

3. Is there a significant relationship between blue light exposure (in hours of gadget use

before sleep) and sleep quality?

4. What measures can be recommended to minimize the negative effects of blue light

exposure on sleep quality?

Hypothesis

 Null Hypothesis (H₀): There is no significant relationship between blue light exposure

and sleep quality among senior high school students.

  Alternative Hypothesis (H₁): There is a significant relationship between blue light

exposure and sleep quality among senior high school students.

Significance of the Study

This study is important for the following groups:

 Students – Provides awareness of how excessive gadget use before bed impacts their

health and academic performance.

 Parents – Offers insights on how to guide their children toward healthier digital and

sleeping habits.

 Teachers and Schools – Serves as a foundation for integrating digital wellness in health

education and implementing school-based sleep hygiene programs.

 Health Professionals – May provide baseline data for campaigns addressing sleep

deprivation in adolescents.

 Future Researchers – Acts as a reference for further studies on technology use, sleep,

and adolescent health.

Scope and Delimitation

This study focuses on the relationship between blue light exposure from gadgets and the sleep

quality of Grade 11 and 12 senior high school students in selected schools. The scope is
limited to gadget use within two hours before bedtime. Other variables such as caffeine intake,

exercise, and psychological stress are not directly measured.

CHAPTER II

REVIEW OF RELATED LITERATURE

Foreign Studies

Chang et al. (2015) found that reading from light-emitting devices before bedtime not only

delays sleep onset but also reduces alertness the following morning. Their study concluded that

the short-wavelength blue light emitted by gadgets suppresses melatonin, a hormone critical for

sleep regulation.

Harbard et al. (2016) studied adolescents in Australia and reported that those who used gadgets at

night experienced sleep restriction and reported feeling fatigued during school hours. They

highlighted that adolescents are particularly vulnerable because their circadian rhythms are

naturally shifted toward later sleep times.

According to the National Sleep Foundation (2019), teenagers who used electronic devices for

more than two hours before bed were more likely to have trouble falling asleep, had shorter sleep

duration, and woke up feeling less refreshed.

Local Studies
De Guzman (2020) conducted a study in Metro Manila and found that high school students using

gadgets late at night often reported sleeping fewer than six hours daily. The study concluded that

excessive gadget use contributed significantly to delayed bedtimes.

Santos (2021) examined students in Davao City and found a strong correlation between poor

sleep quality and lower academic performance. Students with irregular sleep cycles were more

prone to tardiness, absenteeism, and reduced classroom participation.

Another study by Reyes (2022) highlighted that Filipino adolescents often neglect sleep hygiene

practices due to social media usage, with most admitting to staying online past midnight.

Synthesis

Both foreign and local studies agree that blue light exposure affects melatonin production and

reduces sleep quality. While foreign studies focus on the physiological effects of blue light, local

studies emphasize academic and behavioral outcomes. This research combines these perspectives

to examine both the biological and lifestyle consequences among Filipino senior high school

students.

CHAPTER III

METHODOLOGY

Research Design

This study uses a quantitative-correlational research design to determine the relationship

between gadget use (blue light exposure) and sleep quality.

Respondents

The respondents are 100 senior high school students from different strands (STEM, ABM,

HUMSS, TVL). Stratified random sampling ensures equal representation across strands.

Research Instrument

 Survey Questionnaire: Measures the number of hours spent using gadgets before bed.

 Pittsburgh Sleep Quality Index (PSQI): Standardized tool for measuring sleep quality,

covering duration, latency, and satisfaction.

Data Gathering Procedure

1. Permission from school authorities will be obtained.

2. Consent forms will be distributed to participants.

3. Respondents will answer the survey anonymously during designated periods.

4. Data will be collected, tabulated, and analyzed statistically.

Data Analysis

 Descriptive statistics (mean, percentage, frequency) for screen time and sleep quality.

 Pearson correlation to determine the relationship between screen time and sleep quality.

 Regression analysis to test the strength of prediction between variables.

CHAPTER IV

PRESENTATION, ANALYSIS, AND INTERPRETATION OF DATA

Table 1: Average Screen Time Before Bedtime

Screen Time (Hours) Frequency Percentage

0–1 hour 10 10%

1–2 hours 25 25%

2–3 hours 30 30%

3–4 hours 20 20%

4+ hours 15 15%

Interpretation: The majority of students (65%) spend more than 2 hours on gadgets before

sleeping.

Table 2: Sleep Duration of Respondents

Sleep Duration (Hours) Frequency Percentage

Less than 5 hours 18 18%

5–6 hours 40 40%

6–7 hours 30 30%

7–8 hours 10 10%

8+ hours 2 2%
Interpretation: Most students sleep for only 5–6 hours, below the recommended 8–10 hours for

adolescents.

Correlation Analysis

Pearson’s r = -0.62, showing a moderate negative correlation between gadget use and sleep

quality. The longer the screen time, the poorer the reported sleep quality.

CHAPTER V

SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

Summary

This study investigated the effect of blue light exposure on the sleep quality of senior high school

students. Results show that the majority spend 2–4 hours on gadgets before bed. Students

averaged only 5–6 hours of sleep, and most reported difficulty falling asleep and feeling unrested

upon waking. Statistical analysis revealed a significant negative correlation between screen time

and sleep quality.

Conclusions

1. Students spend excessive time on gadgets before sleeping.

2. Sleep quality among senior high school students is generally poor.

3. There is a significant negative relationship between blue light exposure and sleep quality.

4. The null hypothesis is rejected.

Recommendations

 For Students: Limit gadget use before bedtime and enable blue light filters.

 For Parents: Encourage healthy digital curfews and nighttime routines.

 For Schools: Incorporate digital wellness programs into the curriculum.

 For Future Researchers: Explore interventions like blue light glasses and their

effectiveness in improving sleep.

REFERENCES

 Chang, A. M., et al. (2015). Evening use of light-emitting eReaders negatively affects

sleep, circadian timing, and next-morning alertness. PNAS.

 Harbard, E., et al. (2016). Sleep and adolescent use of technology. Journal of Adolescent

Health.

 National Sleep Foundation. (2019). Sleep in America Poll.

 De Guzman, R. (2020). The effects of gadget use on the sleeping habits of Filipino high

school students. Philippine Journal of Education.

 Santos, M. (2021). Poor sleep quality and academic performance among senior high

school students. Davao Research Journal.

 Reyes, J. (2022). Sleep hygiene practices and technology use among adolescents. Journal

of Philippine Psychology.