Why do optometrists need to administer eyedrops that force your eyes to dilate before they examine your eyes with their bright lights?

In general in which direction does wind blow

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a.an ionic bond is formed between the oxygen and carbon atoms. b.four valence electrons are shared. c.two valence electrons are shared. d.valence electrons are shared between oxygen atoms.

Which factor that affects biodiversity?