The answer is yes, love at first sight exists. So much so that when you meet your soul mate, when you meet your partner, something in you leaps up, that you feel like opposite sides of a magnet attracting each other. So in that angle, love at first sight does exist.
Love is an intimate personal activity that seeks, the happiness, the welfare and the safety of another. When you love somebody, you care for them, you are interested in their happiness, you do things for them, you are interested in their safety, so you make sure they have security, you try your personal best to make them happy all the time, so that is love. I like what the scripture talked about love in first Corinthians, chapter thirteen verses one to thirteen, where the virtues of love were being talked about. Love is not arrogant, it is not boastful. Love seeks to protect. Of the good virtues, love is the greatest. Jesus Christ actually told us to love our neighbour as we love ourselves. So at this point what is there not to love about love.