MDS Treasurer
Great weather, a delicious orange chiffon cake, a great speaker and a very engaging audience …. This sums up our talk on refractive errors, UV protection and glasses.
When I was younger, my world of eyesight revolved around myopia and astigmatism. When my parents aged, I learnt of Hyperopia (long-sightedness). Even then, these were terms I never understood in depth. From last Saturday’s session, my vocabulary increased by another word Presbyopia and Fifianna also went through a thorough and clear explanation of what all these meant.
In short (very short), by definition:
Myopia
- Short-sightedness which occurs through i) Axial Myiopia (the length of the eyeball is longer than “normal”) OR ii) Refractive Myopia (refractive power of the eye is higher than “normal”)
- Light rays entering the eye are focused in front of the retina.
- Myopia increases risks of retinal detachment, cataract, glaucoma and age-related or myopic macular degeneration.
Hyperopia
- Long-sightedness which occurs because the length of the eyeball is shorter than normal and the refractive power of the eye is lower than “normal”.
- Light rays entering the eye are focused behind the retina.
- Hyperopia can cause eye strain, headaches and intermittent blur vision.
Astigmatism
- Occurs due to an irregular curvature of the surface of the cornea.
- Usually occurs with myopia or hyperopia.
- Light rays entering the eye are focused on 2 points, rather than 1.
Presbyopia (Old-Sightedness)
- Occurs when the crystalline lens loses its flexibility
- Usually begins around the age of 40
- May occur in addition to other refractive errors such as myopia, hyperopia or astigmatism
- Visual disturbance due to presbyopia
- Blurry near vision when reading, sewing, computer work or other near tasks
Prescriptive Glasses - Choosing the right type
Lens Selection
There is a wide variety to choose from for lenses. There are single vision lens, bifocal lens and progressive addition lens. There are also different types of lens materials like glass (with different features like multicoating, UV coating, hard coating etc), plastic and polycarbonate. Again, comfort is key.
Frame Selection
There is a wide variety of metals, plastics and other types of frame (wood/bone/buffalo hone etc) available in the shops. Comfort is key. Frame shapes and colours can help bring out your features. Here’s a tip from Fifianna with regards to frame shapes.
Ultraviolet Light Protection
As most of us are aware, we need to protect our eyes from UV-A and UV-B. Especially in Singapore where the rays are strong because we sit on the equator. Like applying sunblock when we go to the beach, we need constant protection for our eyes. If you are not convinced, here’s a list of eye problems that could arise and hopefully, this will prod you into better eye habits.
As most of us are aware, we need to protect our eyes from UV-A and UV-B. Especially in Singapore where the rays are strong because we sit on the equator. Like applying sunblock when we go to the beach, we need constant protection for our eyes. If you are not convinced, here’s a list of eye problems that could arise and hopefully, this will prod you into better eye habits.
- Photokeratitis - damage to the outer layers of the cornea due to exposure to intense light
- Pterygium - triangular thickening of the conjunctiva that may grow onto the cornea and interfere with vision
- Pinguecula - benign yellowish thickening of the normal conjunctival tissue
- Cataract - loss of transparency of crystalline lens
- Age-related macular degeneration (AMD) - research suggests that UV-A rays may play a role in degeneration of macula
- Climatic Droplet Keratopathy - accummulation of translucent materials in the superficial corneal stroma
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