So what I'd like to focus on in this lecture is cataract formation. So how does the build up of the galactos actually lead to cataract formation? Well, what exactly is a cataract? Well, cataract quite literally means there's a wall of water that exists in the length of our eye and that basically decreases the transparency of the lens and so we essentially become blind so we can't see very well. Now how does an increase in galactose actually lead to the building of a cataract? Well, inside the lens we essentially have cells and when the cells when there's an increase in the galactose concentration inside the cell the galactose begins to slowly convert into the galactitol as a result of the activity of the Aldos reductase.