The fact that we observe in case of refraction through prism is, the ray gets bent or deviated towards the base of the prism. So in case of a convex lens you can imagine many prisms have been packed...
Your are mixing properties. Converging lens is always thicker in the centre and thinner at the edges. The other cathegory is the geometry of shape of the surfaces of the lens. Convex means that the...
They are used mainly for better sight.Here's an example of each.Convex is shaped like this ) which gives a wider angle.They are often used in convenience stores.Concave are used in side mirrors of...