Does constant lack of sleep lead to cataracts?

No. No association known.
Doubt it! The bluriness you are seeing are likely due to fatigue and dry eyes!
No. More likely this will lead to eye fatigue and eye dryness which can affect vision, and eye drops can help temporarily. Good sleep is essential to being healthy.

Related Questions

Does lack of sleep cause cataracts?

No. There is no relation between the development of cataracts and sleep patterns.