Today Year 9 scientists dissected sheep’s eyeballs to learn about the structure and function of the different parts. Did you identify the cornea, iris, pupil, lens, retina, vitreous humour and optic nerve? We obtained the eyeballs from the local abattoir and used sharp scalpels, scissors and forceps to firstly trim the fat and muscle from around the eye and then cut a small window, just behind the iris. Then we cut carefully around the brown-coloured iris to remove the cornea and iris. Inside the eyeball was a clear, jelly-like substance (vitreous humour) and the lens. The retina was brightly coloured – a shiny blue/green surface at the back of the eyeball, where the image is focussed. The optic nerve transmits nervous impulses to the brain.
While I am away at Professional Development on Monday and Tuesday, you can start your assessment piece for the unit of work we have just finished – “Light”. You are to create a poster, Powerpoint, video, Voicethread or Photostory that describes how a light-dependent piece of technology works – a microscope, telescope, binoculars, optic-fibre camera, theodolite (instrument that surveyors use), camera etc. Go to “How Stuff Works”: Light Microscope, Telescopes, Corrective lenses, Sunglasses, Binocular vision.
Make sure your project demonstrates your understanding of the following terms: reflection, refraction, absorption and polarisation. This project will be due on Friday 19th September.
