Color Vision 5 Flashcards
This type of color deficiency means absence of color.
Achromatopsia
- very rare
Incomplete achromatopsia has what type of PRs left? Complete?
- Long and M cones (reduced function)
- Only rods present
What is the tx for achromatopsia? What does it prevent?
- Dark Red Lenses
- Prevents rod bleaching and helps with photophobia
What PRs are functional in blue monochromacy?
- rods and S-cones
What is the treatment for blue monochromacy?
Magenta Glasses
This is a disturbance of vision where colored objets appear unnaturally colored. Usually following cataract extraction or drug use.
Chromatopsia (not a true color vision anomaly)
Color Anomalies are caused by what?
cross-overs of genetic information during meiosis
What is the less severe type of crossover? Inter or intragenetic?
Intragenetic = only part of the gene crosses over (hybrid); Intergenetic = entire gene grosses over; more severe
Acquired color deficiencies can occur ______ along the visual pathway.
anywhere
Kollner’s rule states what?
BY defects = outer retina or media changes
RG defects = diseases of the conduction pathway (inner retina to visual cortex)
If patient has non-selective color vision loss (both RG and BY), what disease are you worried about?
Multiple sclerosis
- optic neuritis (but typically RG)
In glaucoma, early color vision losses are what defect?
Blue yellow
Tritan-like defects are found in what 3 ocular diseases?
- ARMD
- Central Serous Retinopathy
- Diabetic Retinopathy
Digoxin/Digitoxin produces what type of defect?
RG
Viagra produces what type of defect?
BY
Chloroquine produces what type of defect?
- BY initially
2. Protan defect later
Ethambutol produces what type of defect?
RG
Industrial chemical produces what type of defect?
BY
Which cone is more vulnerable to disease?
S cones
SWAP is great to use for glaucoma because?
- S-cones are damaged first
- only make up 5% of ganglion cells
- if few are damaged, easier to detect
What are the 2 ways that filters work?
- move color confusion lines
2. block specific wavelengths
An X-chroma lens improves color vision by doing what 2 things?
- lets long wavelengths through filter
2. Blocks shorter wavelengths
What effect does an X-chroma lens have on a monochromat? dichromat?
- monochromat becomes dichromat
2. dichromat becomes tetrachromat
The enchroma lens improves color vision by doing what 2 things?
- Separates M and L wavelengths to increase color perception
- blocks some wavelengths
What is the only lens that is FDA approved to treat dyslexia?
Chromagen Lenses
These type of lenses corrects RG defects by amplifying oxygenation of blood under the skin.
Oxy-Iso glasses
The luminance function peak for deuteranopes is similar to who?
Trichromats
