Back in 2002, Bausch & Lomb funded research conducted by the Faculty of Life Sciences at The University of Manchester that determined a method to measure the effects of "beer goggles". They made a mathematical equation to do this:
An = number of units of alcohol consumed
S = smokiness of the room (graded from 0-10, where 0 clear air; 10 extremely smoky)
L = luminance of 'person of interest' (candelas per square metre; typically 1 pitch black; 150 as seen in normal room lighting)
Vo = Snellen visual acuity (6/6 normal; 6/12 just meets driving standard)
d = distance from 'person of interest' (metres; 0.5 to 3 metres)
The formula can work out a final score (B), which can range from less than one (where there is no beer goggle effect) - to more than 100 (with a HUGE beer goggle effect). The higher the number, the more attractive an otherwise unattractive person will appear.
Although heavier drinking can lead to temporary strabismus and amblyopia, it is still unnclear whether alcohol has a direct effect on the optic nerve. Strabismus is a disorder in which the eyes do not line up in the same direction when focusing. The condition is more commonly known as "crossed eyes." Amblyopia can be caused by a condition called ptosis, which is a drooping of the eyelid.
Alcohol amblyopia is a visual condition unique to those who have a history of chronic, severe drinking problems. The disorder involves lost vision, including scotomas (blind spots) and decreased visual acuity within the central portion of the visual field. The painless, bilateral sight loss gradually worsens. The disorder is caused by the toxic effects of alcohol on the optic nerve causing optic neuropathy, a condition in which the optic nerve swells. Because alcohol depletes the entire body system of nutrients, alcohol amblyopia is easily linked to a thiamine (vitamin B1) deficiency, a condition that can lead to optic-nerve damage. The condition can be treated with proper diet and vitamin supplementation. It is generally reversible, but may lead to permanent vision loss if untreated.
Alcohol is a depressant drug (Sedative-Hypnotics). Depressants are
habit forming drugs which can lead to severe addiction problems. Among
the most abused depressant drugs is Alcohol.
Alcohol is used to relax the nervous system. One of the most rapid
affects of alcohol is on the central nervous system (CNS), which
controls a range of vital body functions; the sense organs, muscles
controlling speech as well as the sweat glands in the skin. The nerves
which leave the spinal cord and brain comprise the peripheral nervous
system. Your peripheral nervous system consists of 12 pairs of cranial
nerves, which emerge from your brain and mainly serve
your head and neck. It also contains 31 pairs of spinal nerves, which branch off from your spinal cord and supply the rest
of your body.
In normal circumstances the CNS receives sensory information from
organs such as the eyes and ears, it analyses the information and then
initiates an appropriate response e.g. contracting a muscle.
But when alcohol (toxins) interfere the CNS's ability to analyse
sensory information resulting in the typical symptoms of being drunk
such as disturbed balance, slurred speech, blurred vision, heavy
sweating and the dulling of our sensation of pain, and even loss of
consciousness and possibly death.