The eye

• Sensory systems


  The parts of the body that allow us to see, hear, taste, smell, and feel
• Eye


  • Lens
  • Retina
  • Aqueous Humour
  • Pupil
  • Iris
  • Optic Nerve
  • Cornea
  • Ciliary muscles
  • Blind spot
  • Tapetum (Choroid)
  • Sclera
• How the eye works

  1. Lens directs light rays onto the retina

  2. Retina forms a picture

  3. Picture is sent to the brain
• Eye malfunctions


  • Cataracts
  • Diabetes-related retinopathy
  • Glaucoma
  • Age-related macular degeneration
• Cataracts


  Lens develops cloudy patches, causing blurry, misty vision and eventually blindness
• Causes of cataracts


  • Diabetes
  • Eye injury
  • Inflammation
  • UV exposure
  • Smoking
  • Family history
  • Alcohol intake
  • Steroid use
• Cataract symptoms


  • Cloudy or blurred vision
  • Trouble with bright light
  • Glare issues
  • Difficulty seeing colours
• Cataract diagnosis and treatment


  • Eye test
  • Visual acuity exam
  • Surgery
• Retinopathy


  High blood sugar damages the retina, causing narrowing and leakage of blood vessels, which can lead to blindness
• Retinopathy symptoms


  • Gradually worsening vision
  • Sudden vision loss
  • Shapes floating in vision
  • Blurred or patchy vision
  • Eye pain or redness
  • Difficulty seeing in the dark
• Retinopathy diagnosis and treatment


  • Screening test
  • Blood pressure test
  • Laser treatment
  • Injections of medication
  • Surgery to remove blood or scar tissue
  • Healthy lifestyle changes
• Glaucoma


  Eye disorder that damages the optic nerve, leading to vision loss, often caused by fluid buildup in the eye
• Glaucoma risk factors


  • Family history
  • High blood pressure
  • Long-term steroid use
  • Near-sightedness
  • Previous eye injury or surgery
• Glaucoma symptoms and causes


  • Eye pain or pressure
  • Headaches
  • Rainbow-colored halos around lights
  • Nausea and vomiting
  • Red eyes
  • Low vision, blurred vision, narrowed vision, or blind spots
• Glaucoma diagnosis and treatment


  • Dilated eye exam
  • Gonioscopy
  • Optical coherence tomography
  • Pachymetry
  • Eye drops
  • Laser therapy
  • Surgery
• Age-related macular degeneration (AMD)


  Common condition affecting the middle part of vision, usually in people 50s and 60s, can make everyday activities difficult but does not cause total blindness
• Types of AMD


  • Dry AMD
  • Wet AMD (more serious and develops faster)
• Causes of AMD


  • Smoking
  • High blood pressure
  • Being overweight
  • Family history
• AMD symptoms


  • Blurred or distorted vision
  • Seeing straight lines as wavy or crooked
  • Objects looking smaller than normal
  • Colours seeming less bright
  • Seeing things that are not there (hallucinations)
• AMD diagnosis and treatment


  • Optometrist assessment
  • Imaging tests like retinal scan
  • No treatment for dry AMD, but digital technology can monitor vision
  • Wet AMD treated with anti-VEGF injections and sometimes photodynamic therapy
• Side effects of eye injections


  • Red eye
  • Sore and gritty eye
  • Floaters or small specks in vision
  • Flashing lights or swirls of light