Thanks for choosing HCM for your query.
While straining there can be a rise of intra ocular pressure and there can be chance of some bleeding into the gel in the eye ( vitreous ). This is common in people of middle to old age..
If you are a diabetic consult your ophthalmologist as early as possible.
A vitreous hemorrhage
without a predisposing cause generally clears within 2-3 wks.
I will be available for further queries.. Take care..