Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 09-10-2017, 09:16 PM   #21
Purple Haze
 
Join Date: Jul 2006
Default Re: What if you replaced all cones with rods?

Long before Lasik was a thing, I had a friend with 20/5 vision. He could read a newspaper at 20'.
Purple Haze is offline   Reply With Quote
Old 09-10-2017, 09:32 PM   #22
Flyndaran
Untagged
 
Join Date: Oct 2004
Location: Forest Grove, Beaverton, Oregon
Default Re: What if you replaced all cones with rods?

That's slightly better than the best possible assuming human sized pupils due to physics.
He was probably not seeing every letter clearly, but partly guessing based on rules of language.
__________________
Beware, poor communication skills. No offense intended. If offended, it just means that I failed my writing skill check.
Flyndaran is offline   Reply With Quote
Old 09-11-2017, 12:10 AM   #23
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: What if you replaced all cones with rods?

Quote:
Originally Posted by Purple Haze View Post
Long before Lasik was a thing, I had a friend with 20/5 vision. He could read a newspaper at 20'.
Max possible given human pupil size is around 20:10.
__________________
My GURPS site and Blog.
Anthony is online now   Reply With Quote
Old 09-11-2017, 04:19 AM   #24
RyanW
 
RyanW's Avatar
 
Join Date: Sep 2004
Location: Southeast NC
Default Re: What if you replaced all cones with rods?

Quote:
Originally Posted by Anthony View Post
Max possible given human pupil size is around 20:10.
That's what Ted Williams had, which was considered a medical marvel when he had his military physical for WWII.
__________________
RyanW
Height: 5.93 light-nanoseconds
Weight: 13.9 yoctoEarths
RyanW is offline   Reply With Quote
Old 09-11-2017, 07:54 AM   #25
whswhs
 
Join Date: Jun 2005
Default Re: What if you replaced all cones with rods?

Let me add a recommendation: Animal Eyes, by Michael F. Land and Dan-Eric Nilsson (Oxford University Press). It was my single most valuable source for writing GURPS Powers: Enhanced Senses. If you want to write an actual book, you might as well read a systematic survey rather than going by the bits and pieces various of us happen to know and contribute.
__________________
Bill Stoddard

A human being should know how to live fast, die young, and leave a beautiful corpse. Specialization is for insects.
whswhs is offline   Reply With Quote
Old 09-11-2017, 11:20 AM   #26
sir_pudding
Wielder of Smart Pants
 
sir_pudding's Avatar
 
Join Date: Aug 2004
Location: Ventura CA
Default Re: What if you replaced all cones with rods?

My right eye is something better than 20:20. For years I thought my left eye needed correction because my vision is noticeably poorer there, and I always couldn't understand why I was always just waived on after eye tests because I felt certain that I must have failed the left eye portion by being unable to read lines that were fine for my right eye. Turns out my left eye is fine, but my right eye is closer to 20:15. I think this actually has a lot to do with my migraines.

Edit: I can read line 10 mostly on the Schelling chart with my right eye, which I think means that my vision there is between 20/15 and 20/10 but I am having trouble finding explanations for lines 9-11 online.

Last edited by sir_pudding; 09-11-2017 at 11:49 AM.
sir_pudding is offline   Reply With Quote
Old 09-11-2017, 11:37 AM   #27
whswhs
 
Join Date: Jun 2005
Default Re: What if you replaced all cones with rods?

Quote:
Originally Posted by sir_pudding View Post
My right eye is something better than 20:20. For years I thought my left eye needed correction because my vision is noticeably poorer there, and I always couldn't understand why I was always just waived on after eye tests because I felt certain that I must have failed the left eye portion by being unable to read lines that were fine for my right eye. Turns out my left eye is fine, but my right eye is closer to 20:15. I think this actually has a lot to do with my migraines.
Your average mammal has around 20:150-20:200, I think, or -5 to -6. But I went with -4 for the new Bad Sight in Enhanced Senses, to be compatible with other forms of Bad Sight.
__________________
Bill Stoddard

A human being should know how to live fast, die young, and leave a beautiful corpse. Specialization is for insects.
whswhs is offline   Reply With Quote
Old 09-11-2017, 11:53 AM   #28
sir_pudding
Wielder of Smart Pants
 
sir_pudding's Avatar
 
Join Date: Aug 2004
Location: Ventura CA
Default Re: What if you replaced all cones with rods?

Quote:
Originally Posted by whswhs View Post
Your average mammal has around 20:150-20:200, I think, or -5 to -6. But I went with -4 for the new Bad Sight in Enhanced Senses, to be compatible with other forms of Bad Sight.
20:200 (for humans) is legally blind, which might reasonably be a worse condition then either form of Bad Sight (Bad Sight plus a Minor Handicap quirk giving an additional -2 to near or far vision?) .
sir_pudding is offline   Reply With Quote
Old 09-11-2017, 12:12 PM   #29
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: What if you replaced all cones with rods?

Quote:
Originally Posted by sir_pudding View Post
20:200 (for humans) is legally blind, which might reasonably be a worse condition then either form of Bad Sight (Bad Sight plus a Minor Handicap quirk giving an additional -2 to near or far vision?) .
Legally blind means eligible for compensation as if blind, not being actually unable to see. GURPS bad sight is quite severe, it arguably reaches the definition of legally blind.

In terms of actual effects, at a range of 1 yard, 20:20 vision has a resolution of 0.01" (about 1 pixel on a typical monitor). Having a resolution of merely 0.1" will not especially affect anything most animals care about, though for animals with binocular vision it does affect parallax detection (range uncertainty of a couple inches at a range of 1 yard).
__________________
My GURPS site and Blog.
Anthony is online now   Reply With Quote
Old 09-11-2017, 12:16 PM   #30
sir_pudding
Wielder of Smart Pants
 
sir_pudding's Avatar
 
Join Date: Aug 2004
Location: Ventura CA
Default Re: What if you replaced all cones with rods?

Quote:
Originally Posted by Anthony View Post
Legally blind means eligible for compensation as if blind, not being actually unable to see. GURPS bad sight is quite severe, it arguably reaches the definition of legally blind.
20:200 is closer to -6 than -4.
sir_pudding is offline   Reply With Quote
Reply

Tags
basic, science, vision

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 01:40 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.