1. Conjunctivitis
Redness and inflammation of the thin layer of tissue that covers the front of the eye (the conjunctiva) often also irritation and watering of the eyes, sometimes discharge
Causes
Infection by viruses or bacteria
Allergy e.g. pollen or dust mites
Irritants e.g. shampoo, chlorine
Treatment
Eye hygiene
Bacterial conjunctivitis – may benefit from antibiotic
Most get better without treatment, within 1–2 weeks
Usually use of antibiotic makes little difference to recovery
Up to 10% of people treated complain of adverse reactions to treatment
The risk of a serious complication from untreated infective conjunctivitis is low
Irritant conjunctivitis – remove the irritant
Allergic conjunctivitis – antihistamine and remove the allergen
Avoid contact lenses until better, washing hands regularly
Work and school
Public Health England (PHE) advises that you don't need to stay away from work or school if you or your child has conjunctivitis

2. Dry Eyes
Where your eyes don't produce enough tears or your tears evaporate too quickly
Causes
Hormonal changes (pregnancy, menopause, contraceptive pill)
Ageing
Environment (sun, wind, smoke)
Activities (reading, writing, working with a computer)
Medications (antihistamines, antidepressants, beta-blockers, diuretics)
Laser eye surgery
Contact lenses
Medical conditions (allergic conjunctivitis, eczema, Sjögren's syndrome, rheumatoid arthritis, lupus, scleroderma, Bell's palsy)
What can help
Wrap-around glasses/eye protection
Avoiding irritants e.g. eye make-up
Adjust your computer, limit continuous use
Humidifier or air filter
Eye hygiene
See your optician for advice on over the counter products that may help

3. Blepharitis
The edges of the eyelids become red and swollen, feel itchy, sore and can stick together, often a burning or gritty sensation in your eyes
Usually both eyes, and symptoms tend to be worse in the morning
See your high-street optician if you have persistent symptoms that aren't being controlled by simple measures
Causes include a reaction to bacteria or fungi on the skin, a skin problem such as rosacea or eczema
It isn't contagious
Usually long-term, may come and go
More severe cases may occasionally require antibiotics

4. Eye Hygiene To be done once or twice a day, ongoing
use a warm compress – to make the oil from glands around your eyes more runny
gently massage your eyelids – to push the oils out of the glands
clean your eyelids – to wipe away excess oil, unblock glands, remove bugs. Using a solution of 1 pint cooled boiled water to 1 tsp bicarbonate of soda

5. The red eye, when to worry
See your GP immediately if
Eye pain
Sensitivity to light
Disturbed vision
Intense redness in one eye or both eyes
A newborn baby with conjunctivitis 
Suspect a foreign body
Glaucoma or iritis history
Chemical injury
Trauma
Contact lens wearers