The prolonged use of electronic products triggers three major health risks: forward head posture (60° low cervical spine pressure 28kg ≈ equivalent to a 28kg load), requiring to adjust the posture every 30 minutes; screen blue light disrupts melatonin production causing insomnia, it is recommended to stay away from the electronic devices before going to bed; indoor addiction displaces the outdoor time (children need to be vigilant about developmental delays). The core of the solution is the intermittent usage principle - sedentary ≤ 90 minutes/per session, eye exercises follow the 20-20-20 principle, ensure daily outdoor exposure. Instead of resisting tech devices, it is better to strategically adjust: maintaining cervical alignment, regulating sleep cycles, and prioritizing sunlight exposure are the guidelines for a healthy life in the digital age.

Vitamin A is essential for vision, immunity, and child development, and the risk of deficiency in children is five times higher than in adults, with night blindness being a typical manifestation. Animal foods such as milk (choose full fat), eggs, and animal liver are good quality sources. Plant-based sources include red-orange vegetables like carrots. One egg per day for children and 500ml of milk plus eggs in the morning and evening for adults is sufficient to meet the target. It is important to be aware of the upper limit of intake (10mg/day for adults, 7.5-15mg for children), as excessive amounts may be toxic.

COVID-19 lockdowns put immune systems on a global "pause". The Lancet reported that children weren't exposed to viruses in 99.5% of cases, accumulating an 'immune debt' — essentially rusting and neglected shields becoming ineffective. A study conducted in Soochow University reveals that antibody levels among 1–4-year-olds will have a cliff-like drop by 2023. When infections returned, the cost of immune systems "cramming missed lessons" was retaliatory immune storms; half-empty schools and overstretched pediatric units.