Featured Research

from universities, journals, and other organizations

How Well Do Dogs See At Night?

Date:
November 9, 2007
Source:
University of Wisconsin - Madison
Summary:
Dogs see a lot better than humans do at night. Dogs have many adaptations for low-light vision. A larger pupil lets in more light. The center of the retina has more of the light-sensitive cells (rods), which work better in dim light than the color-detecting cones.

Dogs have good night vision, due in large part to the tapetum, a mirror-like structure which reflects light, giving the retina a second chance to register light that has entered the eye. This is also what makes dogs eyes glow at night. The dog is holding a toy in her mouth.
Credit: Michele Hogan

A lot better than we do, says Paul Miller, clinical professor of comparative ophthalmology at University of Wisconsin-Madison.

“Dogs have evolved to see well in both bright and dim light, whereas humans do best in bright light. No one is quite sure how much better a dog sees in dim light, but I would suspect that dogs are not quite as good as cats,” which can see in light that’s six times dimmer than our lower limit. Dogs, he says, “can probably see in light five times dimmer than a human can see in.”

Dogs have many adaptations for low-light vision, Miller says. A larger pupil lets in more light. The center of the retina has more of the light-sensitive cells (rods), which work better in dim light than the color-detecting cones. The light-sensitive compounds in the retina respond to lower light levels. And the lens is located closer to the retina, making the image on the retina brighter.

But the canine’s biggest advantage is called the tapetum. This mirror-like structure in the back of the eye reflects light, giving the retina a second chance to register light that has entered the eye. “Although the tapetum improves vision in dim light, it also scatters some light, degrading the dog’s vision from the 20:20 that you and I normally see to about 20:80,” Miller says.

The tapetum also causes dog eyes to glow at night.


Story Source:

The above story is based on materials provided by University of Wisconsin - Madison. Note: Materials may be edited for content and length.


Cite This Page:

University of Wisconsin - Madison. "How Well Do Dogs See At Night?." ScienceDaily. ScienceDaily, 9 November 2007. <www.sciencedaily.com/releases/2007/11/071108140336.htm>.
University of Wisconsin - Madison. (2007, November 9). How Well Do Dogs See At Night?. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2007/11/071108140336.htm
University of Wisconsin - Madison. "How Well Do Dogs See At Night?." ScienceDaily. www.sciencedaily.com/releases/2007/11/071108140336.htm (accessed August 23, 2014).

Share This




More Plants & Animals News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Endangered Red Wolves Face Uncertain Future

Endangered Red Wolves Face Uncertain Future

AP (Aug. 22, 2014) A federal judge temporarily banned coyote hunting to save endangered red wolves, but local hunters say that the wolf preservation program does more harm than good. Meanwhile federal officials are reviewing its wolf program in North Carolina. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Farm Resurgence Grows With Younger Crowd

Farm Resurgence Grows With Younger Crowd

AP (Aug. 22, 2014) New England farms are seeing a surge in younger farm hands as the 'buy local' food movement grows across the country. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) According to a new study, spiders that live in cities are bigger, fatter and multiply faster. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins