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.
How diabetes can affect the eyes. The retina is the light-sensitive layer of cells at the back of the eye that converts light into electrical signals. The signals are sent to the brain and the brain turns them into the images you see. The retina needs a constant supply of blood, which it receives through a network of tiny blood vessels.