There are many causes of tiredness. Diabetes is a cause and should be investigated with various tests. HbA1c is a good test that shows sugar levels over the last 3 months, with more emphasis on the last month. A value >48mmol indicates Diabetes. A value from 42-47 indicates the patient is pre-diabetic and lifestyle management should be advised.

This question is pointing to a diagnosis of Giant cell arteritis with classical features being >60 years old, headache, acute loss of vision, unilateral scalp tenderness, Jaw claudication, Pale swollen disc and an ischaemic retina. It is very important on suspicion of this diagnosis to start steroids such as Prednisolone immediately.

The mechanism of pilocarpine is to constrict the pupil thereby pulling the iris away from the trabecular meshwork.

The following are causes of red eye: Conjunctivitis, Episcleritis, Keratitis, Uveitis, Acute closed-angle Glaucoma.