The speed of vision: an insight into sight.

Consider a hummingbird. Smaller brain means shorter connections from eye to brain, meaning quicker perception. We can barely see their movements, and this is to be expected. Elephants: larger brain and slower perceptive ability. This is not a rule, as snails have suboptimal neural systems (in regard to perceptive speed), which results in a slow, albeit short, connection from their eyestalks to central nervous system.
If (and when) humans develop a means of accelerating some of their neural network, the perceptive latency from eye to brain would reduce, much like a hummingbird, and our ability to detect faster motion improves. Similarly, should we implement a computerised proxy between our eye (or equivalent) and brain to amend or clarify the data, the latency would increase.
Not only would this mean a perception of faster, or not-as-fast motion, time itself would be perceived as slower or faster, as our concept of time is an aggregate of our perceptions. 'Time racing' is due to unconscious or excited inattention/forgetfulness, which results in 'smaller' memories constructed over a relatively long time.'Time at a crawl' is due to enhanced attention from impatient, pharmaceutical or meditative neural stimulation without environmental focus to create a single set of memories, thereby constructing many fragmented memories over a relativeley short time period. Furthermore, our pattern-seeking tendency engages at a different level of complexity with these 'fast' and 'slow' eyes. Allow me to elaborate with extreme examples as explanatory architypes.

Fast eyes:
Faster vision, shorter neural connections or faster transfer from eye to brain: for example, Hummingbird.
The fastest eye would see not 'objects' as we perceive them, with imperceptible vibration of nanoscale structures shaking out wavelengths of light which appear as solid surfaces of matte or gloss colour with varying transparency. This eye would see a world with imperceptible motion of objects: a single step would take a week, with miniscule differences in position over time, such that the step appears completely frozen. However, the lines would blur. The invisible vibration of matter in its solid form would become a tightly bound, yet writhing mass of tiny particles (too small to see individually, but visible as an ocean of vibrating dust). The normal aspects of vision would remain, but the texture of the world would gain such vibrant and excited content. The difference between the objects 'table' and 'floor' lose meaning with the perception of the physical continuity and constant nanoscale transfer of particles between the notionally separate entities. The fast eyes are blind to the world of social, and even standard physical interactions: only the small, quick, aspects remain: the trivial and omnipresent, yet hidden and fundamental.

Slow eyes
The slower perception via neural proxy, brain enlargement, or similar; the elephant.
The slow eyes cannot perceive people, for they move too quickly. Rather, the slow eyes see 'peoples': cultures, economies, the patterns of market and mass psychology, the maths of large numbers and the interactions of collective identities, growth of nations, memes, trends and fashions. This slower vision sees far more than the normal eye can see, with the pattern of 'lunches' no longer confused by the 'interim meals': a normal human vision would see the banal routine of a day, but slow eyes see the pattern of life as the motion of trends. By focusing upon an element, daily, weekly, annual, centenial routines can all be brought to close comparison and the importance of people and actions becomes truly apparent. With this vision comes great insight into the future and understanding of the past. Much of the depths of psychology and personal identity can be understood as part of a greater organism of 'similar cells with similar design, but different circumstance and function through time'; the human as a mimic and a template, with supportive and instrumental function to a people.

These two 'eyes' are the polar extremes to a scale gradient of potential experience (and not even the absolutes of the scale). The placement upon the scale is proportional to the degree of perceptive alteration.

Now here's the important part: we can all already conceive of reality through these eyes; they are mere frames of reference or perspective shifts. Yes, they can be permanent alterations or defining differences between organisms, but the imagination can allow us to aggregate our knowledge and simulate experience. Why would you simulate a change in time's perceived pace? To gain the greater understanding of reality and its machinations. Were I to elaborate upon this point, I would fall prey to repetition.