History
A detailed history allows the ophthalmologist to triage patients appropriately. In addition to the classic clerking, important red flags meriting discussion with the on-call ophthalmology team include any of:

• Sudden vision loss
• Photophobia
• Pain on eye movement
• Double vision (diplopia) – especially if binocular (see below)
• Flashing lights
• Associated headache/fever
• Abnormal pupil reactions
• Bleeding/trauma to the eye 
• Consider whether an acute red eye could be a foreign body or chemical injury as these could be sight-threatening
• Temporal tenderness/jaw claudication

Beyond these questions, do include

• Past ocular history: previous eye surgery, laser, trauma, contact lens/prescriptions & any known conditions
• Any history of chronic or autoimmune conditions (as many have eye manifestations)
• Drug history: patients don’t often volunteer the eye drops they take without asking!
• Smoking

Examination:
You’ll be surprised how many people don’t examine the “normal” eye. Ensure you examine both! Document clearly what is right & left. By convention, everything is documented as though you are looking at the patient (right eye on the left of the page). The exception is visual fields which are recorded as though the patient is looking through the page (so right eye is on the right of the page).

Ensure you have an order to not miss anything e.g. general inspection of the face, vision, pupils, the eyelids, anterior surface of eye +/- fluorescein staining. Direct ophthalmoscopy is frequently done poorly and is usually not crucial.

General Inspection:

• Facial asymmetry & brow position
• Globe position – vertical or horizontal displacement, proptosis
• Facial swelling/erythema/rashes

Vision:

• Visual acuity
• Ensure they’re wearing their corrective glasses/contact lenses (and document this or if they’re unaided). Pinhole is usually difficult to find.
• If a Snellen chart is unavailable, you can use printed material
• Colour vision with Ishihara (available on the internet or apps)
• Visual Fields – any field losses or obvious enlargement of the blind spot

A good app to use is Eye Test Free

Eye movements:

• Check with both eyes open
• If diplopia is present, check whether it is monocular or binocular
• Binocular diplopia disappears if either eye is covered. It indicates a more serious central/cranial neuropathy as the eyes are not synchronised. Refer this urgently.
• Monocular diplopia may indicate issues with the cornea, lens or macula
• Nystagmus (which can be normal on maximal adduction/abduction)

Pupils:

• Assess their shape
• Pupillary reflexes such as their reaction to light (measure their size in the light & dark)
• Afferent defects: both pupils will constrict in response to light shone in the normal eye, but not if shone in the abnormal eye. The eyes still respond to accommodation
• Efferent defects: fixed dilated pupil in the abnormal eye. However, the other “normal” eye still constricts to light being shone in the abnormal eye
• Relative Afferent Pupillary Defect (RAPD)
• Indicates unilateral or asymmetrical optic nerve dysfunction
• Move a light source back and forth between the eyes. In an eye with RAPD, the pupil will initially dilate when light is shone on it. This is due to the brain perceiving the light as dimmer than in the normal eye due to optic nerve dysfunction  
• Reaction to accommodation

Lid/lashes:

• Review any lumps, swellings, erythema or cellulitis
• Always escalate inflammation around the eye as cellulitis around this area could represent preseptal or orbital cellulitis. The latter is sight-threatening. 
• The lid may be everted/outward turning (ectropion) or inverted (entropion)
• Inward turning of the lashes can be irritating (trichiasis). Loss of eyelashes can be associated with malignant lesions e.g. BCC. 
• Ptosis
• Often due to an ineffective levator muscle
• Can be due to Horner’s syndrome (mild ptosis, miosis)
• Oculomotor palsy (eye movements affected & dilated pupil)

Conjunctiva:

• Circumferential injection (redness) is suggestive of intraocular pathology e.g. acute angle-closure glaucoma, keratitis, uveitis
• Diffuse/sectoral injection usually suggests conjunctivitis (bacterial, viral & allergic) 
• Discharge can be purulent (bacterial) or watery (foreign body, allergic/viral conjunctivitis, corneal abrasion or lacrimal tissue)

• Assessment can be useful to identify clarity, opacities & with fluorescein staining epithelial defects such as corneal abrasion or ulcers. 
• Corneal ulcers often appear as white opacities whereas dendritic ulcers are tree-branch shaped suggestive of herpetic disease

Direct ophthalmoscopy:
This is rarely done well & rarely helpful due to absent or poorly functioning equipment, suboptimal conditions & as doctors don’t regularly use it. It rarely changes the management of a patient in whom other components of the history or examination already necessitate urgent ophthalmology review.

For completeness the components are:

• Red reflex (absence may suggest cataract or vitreous haemorrhage)
• Ideally dilated fundoscopy (after checking pupils) – do document which eye, the drug used and time of dilation
• Optic disc – haemorrhages, pallor or oedema
• Retinal vessels – flame-shaped haemorrhages, silver wiring, tortuosity, emboli
• Retina – cotton wool spots, haemorrhages, pallor
• Macula – drusen, haemorrhages, cherry-red spot