Our chief end. ( Romans 8 v 18 )

I read the following in a devotional called ,Streams in the Desert', by L.B.Cowman.When Dr Moore ,of Brighton ,England, was suddenly struck down with blindness, he said,''Lord ,I accept this 'talent  ' of blindness  from You. Help me to use it for your glory so that when You return , you may receive it 'back with interest' ( Matt 25 v 27 )'' Then God enabled him to invent the Moon Alphabet for the blind, through which thousands of blind people were enabled to read the word of God and thereby come to the glorious saving knowledge of Christ'