Left cornea

Looks like

The clear dome at the front of the eye, over the iris and pupil, about half a millimetre thick.

What it does

Lets light in and does most of the eye's focusing; highly sensitive to touch.

Keeping it well

Scratches, infections (contact lens wearers) and ulcers threaten sight. A painful red eye with blurred vision needs same-day care.

Related conditions

• Blepharitis & styes
• Cataract
• Conjunctivitis
• Corneal abrasion (scratched eye)
• Dry eye disease
• Hyperthyroidism & Graves' disease
• Keratitis (corneal infection and ulcer)
• Keratoconus
• Onchocerciasis (river blindness)
• Presbyopia
• Pterygium (surfer's eye)
• Retinal detachment
• Retinoblastoma
• Short and long sight (refractive error)
• Sjögren's disease
• Squint & lazy eye
• Trachoma
• Uveitis & iritis