Guys i need the know what is the best counterpoint for using a smartphone is bad for your eyes?

Digital devices, smartphones included, emit what we call the blue light. It has a wavelength between 380 to 470 nm. This is the only light that can penetrate the retina of the eyes. Hence, prolonged exposure to blue light, especially during at night, will cause damage to the retina resulting to sleep disorders or worst, cataracts.

in my opinion, ap calculus was the most difficult. i often struggled with it a lot. however, i have gotten a lot better.

what do you mean