Envision Optical
Optometrist in QLD and NSW

Why do pupils dilate?

August 28, 2013
Posted By: Envision Optical

The pupil is the black hole in the middle of the coloured part of the eye, the iris. The pupil’s function is to allow the correct amount of light into the eye to facilitate image formation and vision. The size of the pupil will vary depending on the levels of light we are seeing in.  Small for bright light and large in dim light levels. So a pupil will dilate in low light levels to allow the maximum amount of ambient light into the eyes to achieve the best vision in that light level.

Pupils will also dilate if we are very scared, take certain medications or even dilate constantly and not return to normal size from tumours and vascular damage in the brain that affects the nerve pathway running to the pupil. If your pupils change in size permanently, always see your optometrist for a check to make sure everything is fine.

Both practices are open and following the QLD and NSW Health guidelines for health practices. As we have since the pandemic began, we follow high-standard policies and procedures around health and cleanliness to ensure your and our safety are prioritized and maintained. We care about our community and appreciate your support when visiting us. Please ensure you stay home and reschedule your appointment if you have any symptoms or are a close contact. Masks are required to be worn for all consultations. Please discuss with your optometrist if you have an exemption. If you are stuck in isolation and have eyecare needs, please call or email and we'll do our very best to help. Telehealth consultations and home delivery options are available. For more information please click here or give us a call.