4
votes
2answers
78 views

contact solution on shabbat

I use a contact solution that is hydrogen peroxide based. That is, the solution is hydrogen peroxide. The solution is put into a special case with a platinum disc at the bottom. The disc acts a ...
4
votes
2answers
135 views

Exercises to prevent eyes tiring

It often happens to me that after learning the whole day and reading lots of text especially with small letters I feel my eyes very tired. Who knows good set of exercises that don't takes lot of time, ...