Inferior rectus

Looks like

A strap muscle below the eyeball, running from the tendon ring at the back of the orbit to the underside of the eye.

What it does

Turns the eye downward, most strongly when looking outward, as when reading or walking downstairs.

Keeping it well

Powered by the oculomotor nerve. Most often enlarged in thyroid eye disease; can be trapped in a fracture of the orbit floor after a blow.

Related conditions

• Blepharitis & styes
• Botulism
• Cataract
• Conjunctivitis
• Fibromyalgia
• Frailty & falls in older age
• Heat exhaustion & heatstroke
• Hyperthyroidism & Graves' disease
• Keratitis (corneal infection and ulcer)
• Keratoconus
• Malnutrition & refeeding syndrome
• Muscular dystrophy
• Myasthenia gravis
• Polymyalgia rheumatica
• Presbyopia
• Retinal detachment
• Retinoblastoma
• Rhabdomyolysis
• Sarcoma
• Sarcopenia
• Sjögren's disease
• Squint & lazy eye
• Tetanus
• Uveitis & iritis