Eye colour

Does eye colour determine a need for sunglasses?

The overall answer to that questions is no – sunglasses should be wore by everyone.  There are however, things that you should be doing depending on whether you have dark or light coloured eyes.  Eye color does not significantly affect the sharpness or quality of your vision. However, the amount of melanin present in your iris can affect visual discomfort in certain situations.

Melanin and your eyes

The density of melanin in your iris determines what colors of light are absorbed or reflected. The higher the concentration of melanin in the iris, the darker the iris color. This means that those with dark eyes experience less visual discomfort in bright, sunny environments because the higher concentration of pigment cells in their irises acts as an internal sun block.  Darker irises also reflect less light within the eye, reducing susceptibility to glare and improving contrast discernment. Thus, it seems that people with darker eyes may have better vision in high-glare situations, such as driving at night.

Light-colored eyes, on the other hand, lack the same kind of protection.  More harmful UV light can pass through lighter colored irises, which may increase your risk for developing cataracts and macular degeneration.

With all of that said, your eyes should always be protected no matter if they are the darkest brown or lightest shade of blue.  Whether you have dark- or light- colored eyes, get in the habit of protecting them with  UV-blocking lenses.

Protecting your eyes with sunglasses

Repeated exposure to UV radiation can cause a number of serious eye problems, including cataracts, pterygiums (overgrowth of tissue from the white of the eye onto the cornea), solar keratopathy (cloudiness of the cornea), cancer of the conjunctiva, and skin cancer of the eyelids.  Protecting your eyes should be top priority and there are a few things that you should keep in mind when purchasing shades:

Sunglasses

All sunglasses sold in Australia must be tested and labelled according to the Australian/New Zealand standard AS/NZS 1067:2003 Sunglasses and Fashion Spectacles. Look for a lens category of at least 2 or preferably 3. Under AS/NZS 1067:2003, sunglasses and fashion spectacles are classified as one of the following:

Lens categories

  • Lens category 0: Fashion spectacles
    These are not sunglasses, as they have a very low ability to reduce sun glare. They provide limited UV protection.
  • Lens category 1: Fashion spectacles
    Like category 0 lenses, these are not sunglasses; however, they do provide limited sun glare reduction and UV protection. Fashion spectacles with category 1 lenses are not suitable for driving at night.
  • Lens category 2: Sunglasses
    These sunglasses provide a medium level of sun glare reduction and good UV protection.
  • Lens category 3: Sunglasses
    Similar to category 2, these sunglasses provide a good level of UV protection. Lens category 3 glasses also provide a high level of sun glare reduction.
  • Lens category 4: Sunglasses
    These are special-purpose sunglasses that provide a very high level of sun glare reduction and good UV protection. Never wear them while driving.

In addition to the five category classifications above, the mandatory standard also covers the following:

  • Also known as variable tint lenses, photochromic lenses may not be suitable for night driving, depending on their transmittance properties (i.e. their ability to reduce sun glare and level of UV protection).
  • Non-conforming lenses have the ability to alter a person’s colour recognition, and in particular the detection of traffic light colours. In some cases these lenses must not be used when driving.

The safest way to make sure you purchase the best sunglasses is to book an appointment with your Optometrist.  They will be able to check the health of your eyes at the same time and provide the best possible choices of frames and lenses.

  Book an appointment with Five Dock Eyecare!