Computer Vision Syndrome (CVS), also known as digital eye strain, is a condition that occurs when an individual experiences visual discomfort and other symptoms after prolonged use of digital devices such as computers, smartphones, tablets, and e-readers. Some common symptoms of CVS include:

1. Eyestrain: This is characterized by sore, tired, or burning eyes.
2. Headaches: Persistent headaches, often starting around the eyes or temples.
3. Blurred vision: Difficulty focusing or seeing clearly.
4. Dry eyes: A sensation of dryness or grittiness in the eyes.
5. Neck and shoulder pain: Discomfort in the upper body due to poor posture while using digital devices.
6. Double vision: Seeing two images of a single object.

CVS is believed to be caused by various factors associated with digital device use, including:

1. Prolonged focusing: Staring at a screen for extended periods without breaks can strain the eye muscles responsible for focusing.
2. Blue light exposure: Digital devices emit blue light, which can contribute to eye fatigue and disrupt sleep patterns.
3. Reduced blinking: People tend to blink less frequently while using digital devices, leading to dry eyes.
4. Glare and contrast: Poor lighting conditions, screen glare, and low contrast on digital screens can strain the eyes.
5. Poor ergonomics: Incorrect posture, improper viewing distance, and inadequate positioning of screens can contribute to eye strain.

To prevent or alleviate computer vision syndrome, you can take several steps:

1. Follow the 20-20-20 rule: Every 20 minutes, take a 20-second break and look at something 20 feet away.
2. Blink regularly: Be conscious of blinking to keep the eyes lubricated and prevent dryness.