Karen is tired and ready for sleep. She flips off her lights and starts walking to her bed. Unfortunately, she steps unexpectedly on a bone her dog left in the middle of the floor. Karen likely stepped on the bone because she did not wait long enough for the process of to kick in which would have allowed her to see better in her dark environment.

Dark adaptation.

Explanation:

Karen didn't wait for the dark adaptation to kick in

The rods are known to be acrived with the decrease in light generating scotopic vision, they allow night vision and need some time to be sensitive to change, this process can take up to 30 minutes for the eye to have adequate vision in the dark , process called dark adaptation

an aneroid barometer is different from a mercury barometer in that it provides readings that increase as air pressure increases.

hope it : )