Complex sentence: Global Cataract Blindness Elimination Initiative is an organization who's goal is to reach the achievement of "Right to Sight" and elimination of preventable blindness by 2020 are both dependent on eliminating cataract blindness, the single largest cause.
Split into simpler sentences: Global Cataract Blindness Elimination Initiative is an organization who's goal is to reach the achievement of "Right to Sight" and elimination of preventable blindness by 2020. Both are dependent on eliminating cataract blindness, the single largest cause.