In the past month 4 birds (that I witnessed) have flown into my windows and broken their necks.

Previous years this never happened.

Location: Coastal North Massachusetts, USA.

Inspection after, eyes are white (blind?). Not sure if this is caused by neck breakage.

Is this happening because they're more birds for some reason?
Is this happening because they are being infected with a local diseases that harms sight?
Both?

Any one else have similar things happening?