Tagged: sight

iSee much better with my glasses!


I used to be quite proud of my excellent vision – the ability to spot street signs from a distance, thread needles and find tiny lost items on the floor. I used to worry a little about the time I spent in front of a computer screen, but my doctor assured me that as long as I took regular breaks and changed my focus frequently, there was no evidence to prove permenant damage was being done. So this year, when my daughter had a splinter I couldn’t see and I stopped reading in bed because my eyes ‘got tired’, I didn’t think about needing glasses.

My father has worn glasses all my life and my mother has a wonderful collection for reading, but my vision had always been 20:20. Except for the time I was pruning the fruit trees and nearly poked one eye out. No permanent damage done – luckily. It was two years later, at the age of 44, that I went for a check up and found that, as happens to many people, my lenses had become less flexible and it was time for spectacles. What a wonderful selection to choose from! Glasses are much more of a fashion accessory now that they were when I was growing up. So, now I have a pair at home and another pair at school (when I can find them!).

Age related macular degeneration is another common disease that affects eyesight, but is more common in people over 50 years of age. So how can you look after your eyes? A healthy, low-fat diet, including fish, nuts, fruit and leafy greens is helpful. It’s also important to have your eyes checked regularly. In the U.S. they have VSP Vision Care for locating the nearest vision doctor, tips, videos and eye charts to download.

I have always admired the late New Zealand Professor, Fred Hollows, for the wonderful work he did to improve eyesight by cataract surgery for indigenous Australians and in many other developing countries. At his site you can donate $25 to restore the sight of a person in a developing country with cataracts or sign up for monthly donations or gifts. Three out of four people in the developing world are living with avoidable blindness due to lack of access to simple treatment and routine surgery. On average, a person living with blindness in the developing world will die within four years of going blind. Perhaps you would consider donating to the Fred Hollow’s Foundation?

Year 6/7 Light and Sound


Our next unit of work in Year 6/7  Science will be Light and Sound. We will learn about luminous, incandescent and fluorescent objects and bioluminescent organisms (such as glow worms, some deep-sea fish and phosphoresence in the ocean.) We will also find out about the structure and function of your eyes and ears. We will find out the answers to the following questions:

  • What makes a rainbow?
  • What are polarised sunglasses?
  • Why can’t you see through tinted windows?
  • How do some animals see in the dark?
  • Why can’t anyone hear you scream in space?
  • What is a wave?
  • Why can’t humans hear sounds that some animals can?

 “How Stuff Works” is a great site for finding out how light and sound work. Some good resources from Scholastic StudyJams here. Recent article from New Scientist about how brain damage can have interesting effects on eyesight. The Bioluminescence Web site has some great information about the living organisms that emit light. Here are some links to some good Sound and Light Experiments you can do at home at Fizzics Education and ACS Chemistry for Life.

Getting an Eyeball full!

Today Year 7 and 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.