Each should be considered carefully before any referral. Test each eye separately with distance glasses if worn, using a Snellen Chart at six metres. If Optician finds cataract, do not refer unless patient has symptoms and wishes for treatment, but do check urinalysis for diabetes. Consider culture if sticky. For chronic or recurrent irritiation referral is of low priority.
Urgent referral is required.
Optic nerve or major retinal damage is likely. To finger movements on confrontation, check each quadrant of each eye separately.