When puppies are round two week old we begin to noticed that the corners of the puppies eyes are opening. This is a sign that they should be fully open in the next 24 to 48 hours. At that time we need to keep the lighting down low to keep them comfortable and to protect their eyes until they adjust.
When their eyes do fully open they will still not be able to focus or see very much, just lights and blurred motion for a few days however this is usually the kick start that get them up walking on all fours. They will be zooming around in no time! When the puppies eyes are fully adjusted they still do not have the best eye sight. To compare, "human eyes have 3 "cones" that detect color and can identify red, blue, green and yellow wavelengths created by light entering the eye. Dogs have 2 "cones" which means they can distinguish blue and yellow but not red and green. This is the same spectrum seen by humans when they have colorblindness. Dogs also have a brightness discrimination about 2 times worse than that of humans and their visual acuity is 4 to 8 times worse than that of humans." (Dog Vision, András Péter 2013)
Here is an example of the difference between what we see and what dogs see using a picture taken with different colour objects placed among the puppies.
The first picture is what we see and the second picture is the exact same picture modified to show what a dog might see. Notice the differences in the red, orange and green objects?
You can try the vision tool with your own pictures https://dog-vision.andraspeter.com/
Things To Think About.
What colour do you think would be the best for dog toys? How would this change between inside and outside designated toys? What colour throw toy would contrast better against a dark or sunny sky or landing in deep grass?
Interesting Reading On Dog Vision
Dog Vision https://dog-vision.andraspeter.com/
Ethology Institute Cambridge Animal Behavior and Learning site http://ethology.eu/the-dogs-color-vision-and-what-it-means-for-our-training/ Miller and Murphy: A more detailed scientific report (PDF) http://redwood.berkeley.edu/bruno/animal-eyes/dog-vision-miller-murphy.pdf