Visual organs
Visual organs are those that help us interpret the world through vision.
Our vision is dependent on light from the sun, which reflects off different surfaces, or sometimes directly, into our eyes. The light first passes through our cornea, when serves to bend or refract the incoming light. The iris (which determines our eye colour), regulates the size of the pupil which controls the amount of light that enters our eyes. The lens focus the light, or image into the retina towards the back of the eye, which is lined with a photosensitive tissue that contains photoreceptors that convert light into electrical signals that travel to the brain through the optic nerve. The brain processes the signals and makes sense of the images that are sent to the brain, which becomes an iconic memory. There are two components to iconic memory: visible persistence, and informational persistence. The degree in which a stimulus remain visible shortly after its offset, it is known as visible persistence. (Colthart, 1980). Studies have shown two key properties of visible persistence: The inverse duration effect (the longer the stimulus lasts, the shorter the persistence after stimulus offset), and the inverse intensity effect (the more intense the stimulus, the briefer its persistence) The duration in which visual information about a stimulus remains available to the observer represents information persistence. This component of iconic memory depends on the duration in which the stimulus has affected the observer. The longer the stimulus, the stronger the information persistence. |
|
Difficulties seeing in the classroom
The most common vision problems experienced by students is nearsightedness and farsightedness, Both can be observed through the following symptoms in the classroom:
1. Students who are nearsighted may squint while looking at text or pictures at the front of the class when sitting at a distance.
2. Students who are farsighted may have difficulty concentrating on text when it is close to them (for example, while reading)
3. Other symptoms of vision problems can consist of eye strain and fatigue, and headaches.
1. Students who are nearsighted may squint while looking at text or pictures at the front of the class when sitting at a distance.
2. Students who are farsighted may have difficulty concentrating on text when it is close to them (for example, while reading)
3. Other symptoms of vision problems can consist of eye strain and fatigue, and headaches.
|
Strategies for helping students with visual difficultiesBelow are some strategies that can be used to aid students who have trouble seeing in class:
1. Sit students who have problems seeing closer to the front of the class. 2. Reduce glare from windows and lights as much as possible. 3. Seat the student with their back against the window. 4. Students with low vision may require more time to finish assignments. |