If you have an older, drafty house, it can be kind of hard to keep temperature even and comfortable from room to room. We get a lot of inquiries here at Birdtricks about how cold is too cold for our parrots. The concerns generally stem from the knowledge that many parrot species originate from warm climates.
Astigmatism in only one eye may cause lazy eye (amblyopia) if present from birth. The affected eye does not 'learn' how to see because the brain ignores the signals it receives. Amblyopia can be treated with eye patching if diagnosed early enough, before the vision pathways in the brain are fully developed.
Astigmatism is a vision condition that causes blurred vision due either to a misshapen cornea or sometimes because of an irregular curvature of the lens inside the eye. Problems with either the cornea or the lens prevents light from focusing properly on the retina. When this happens, vision becomes blurred and/or distorted at any distance. Astigmatism is a common vision condition, and can occur jointly with myopia (nearsightedness) and hyperopia (farsightedness). Most people have some degree of astigmatism. Slight amounts of astigmatism usually don't noticeably affect vision and don't require treatment.