General
3: The human eye
This online synchronous meeting will take place on Date | Time. Attendance is compulsory.
Introduction
The body responds to a variety of different stimuli such as light, sound, touch, temperature, pressure, pain and chemicals (taste and smell).
Visual perception starts with the light emitted from or reflected from an object or a scene entering our eyes through the cornea, pupil and lens. The cornea and the lens help to concentrate and project the light onto a photosensitive layer of cells located at the back of the eyeball —the retina. The lens has the additional function of regulating the focus on objects at different distances by making the necessary adjustments. The amount of light that reaches the retina is regulated by changing the size of the pupil, which is an opening between the cornea and the lens delimited by the iris. The retina is responsible for translating the differences in light wavelength (colour), contrast and luminance into a biological signal. This signal is transmitted through the optic nerve and neuronal pathways to the visual processing areas of the brain.
Only one week is allocated on the ATP for the teaching of the human eye. Because the structure and function of the eye has to be taught, it is important to use diagrams for the teaching and learning of this topic. You will also notice that we have included terminology lists as these are crucial for good performance. Please ensure that your learners do regular terminology activities and tests.
The dissection of the eye is listed in CAPS as one of the investigations that need to be performed to enhance teaching and learning and therefore a video clip was also included.Module overview
This module deals with the human eye. There is a detailed terminology list, followed by the structure and functions of certain parts of the eye, accommodation and the pupillary mechanism and the nature and treatment of visual defects.
Learning outcomes
By the end of this module, you will be able to:
- Draw and label the parts of the eye
- Describe the functions of the different parts
- Briefly explain the changes occurring in the eye during accommodation and pupillary reflex
- Identify and describe the various defects of the eye
- Illustrate the existence of the blind spot
- Illustrate the role of binocular vision in depth perception
- Dissect the eye and be able to identify the different parts of the eye
- Set questions based on the different levels of Bloom’s taxonomy.
Study materials
Module structureUnit 1: The structure and functions of the parts of the human eye
- Review the information relating to this unit by clicking on the link below
- Using a NEW Word document, complete activity 3.1 on pages 3 - 10
- The practical should be completed in your classroom laboratory
- Where you are required to sketch the eyeball (question 2), take a photo of your completed sketch and upload this image file when you submit your final document at the end of this module
- Using the SAME Word document, complete activities 3.2 and 3.3 on pages 12 - 13 of the module guide.
Unit 2: Binocular vision and its importanceBinocular vision means to see with TWO eyes (bi = two). We can focus on one object with both eyes increasing the field of vision. A sharp image falls on each retina. The image from the left eye is always slightly different to the image from the right eye. The two images join in the brain (occipital lobes) and results in stereoscopic vision, which allows us to judge distance, depth and size of objects.
- Complete the practical activity 3.4 on page 14 of the module guide.
Unit 3: Changes that occur in the human eye during accommodation and pupillary reflex
- Review the information relating to this unit by clicking on the link below
- Using the SAME Word document, complete activity 3.5 on page 16 of the module guide.
Unit 4: The nature and treatment of visual defects- Review the information relating to this unit by clicking on the link below
- Using the SAME Word document, complete activity 3.6 on page 22 of the module guide
- Submit your final Word document using the submission tool below.
Subject methodologyThe practical activity below is just one of the many free practical activities that can be found on Ellen McHenry's website (click here) which you can incorporate as a teaching aid in your classroom. Have a look!
Module summaryThis module covers all the requirements for the DBE NSC exams w.r.t. the topic: The human eye. It is very important to be able to identify parts of the human eye on a diagram and to provide the functions of that part. The same applies to accommodation and the pupillary mechanism. The nature and treatment of visual defects must also be covered.