Mr Lyte wrote it as he was going blind. That explains the references to darkness and evening. It isn't really about dying or death at all, it is about losing one of God's greatest gifts, and the realisation that he would need to rely on others for the rest of his life. Of all those, the most steadfast and always present would be his God. He knew he would see again in heaven and that is why he wants to be pointed to the skies - he is asking God to guide his footsteps because he cannot see the way.

LTS