I think for the birds is dangerous about the glass , because they can 't distinguish between the glass an open air . That is because the glass is  transparent and the air is also.
The One-Way Glass is a good way for bird to not be hurt by glass . People can look outside but bird can't  ,it can make birds not try to fly through the glass .
The colorful glass is also a good way. It can make birds know that it isn't open air and they won't try to fly through the glass,but l don't think is good for people to look outside.
About the magnetic field I don't think it is a good way for the problem because there is so many building you can' make all the building a magnetic field,and magnetic field may jamming the cellphone. Maybe it's bad for people body.
So l think the problem will be change in future the bird won't be hurt by t