at first sight
The first time one sees another person or thing. When I met my wife, it was love at first sight. At first sight, I knew that house was perfect for me.
at first sight
COMMON You say at first sight to describe your first impression of someone or something. The problem is trickier than it looks at first sight. The aims of the committee appear at first sight to be admirable. Nothing is ever quite as good or quite as bad as it looks at first sight. Note: You usually use this expression to suggest that this first impression was wrong or incomplete. Compare with at first glance.
at first ˈglance/ˈsight
as things seem at first; judging by first appearances: At first glance, the exam paper looked fairly difficult, but once I got started I found it quite easy.