For example, H-Cl has a dipole. The electrons spend more of their time near the Cl atom (the red end in the diagram below). A dipole-dipole interaction is the attraction between two polar molecules. When they approach each other, the negative end one molecule attracts the positive end of the other.
Eyes sensitive to light can also be caused by viruses or inflammation, such as those found in sinus infections. If you have a cough, aching jaw, blocked nose, headaches and lethargy then it's best to visit your GP for a diagnosis of a possible sinus infection and simple antibiotic treatment.
Some people experience light sensitivity which means they have problems with certain levels of light. Lots of people become more sensitive to light as they get older and some people are naturally more light sensitive than others. Many common eye conditions can also make people more sensitive to light.