KORE,

I,ve never owned cataracts but I can tell you what I did on my 9' sawyer lights. I simply slid the rubber ring that contacts the oarlock toward the blade 2-3". It made a noticeable difference and cost nothing. You have to be careful however not to slide the ring too far toward the blade because as you do this, your hands are closer and closer together as you row as a result so it comes down to what is comfortable.

If the ring on your cataracts is not adjustable (Unable to slide it over your rope wrap) you will probably need some kind of a weight system at the handle.

Good luck.