Posts Tagged vision prescription
When you go to an eye doctor do you walk away not really understanding what just happened? Do you know your diagnosis? Do you know what the prescription means? It should be simple but it’s not and you need to do your homework before your visit.
CAST of CHARACTERS: Ophthalmologists are MDs who do surgery and prescribe medications. Optometrists are ODs who mostly do vision tests for glasses but depending on training and State laws they may also do some of the things Ophthalmologists do. RNs, PAs and MAs assist eye doctors just as they might for any medical doctor. Opticians have a high school degree plus training to fit glasses.
Ophthalmologists may have the highest IQs of any doctor group. Ophthalmology has a reputation for a good life-style and high income. The training programs have huge numbers of applicants and only take the best and brightest. Ophthalmologists are so far from primary care they really don’t know what it is about and the reverse is also true. A high IQ does not guarantee skill at explaining eye problems.
Eye doctors are obviously visually oriented. So, one of the best questions a patient can ask is, “I don’t understand, could you draw a picture?”
The eyes alone seem to have as many things that could go wrong as the rest of the body. But. there are a five topics most people should know about:
- Glasses. What is near-sighted and far-sighted. What do the numbers on the prescription mean.
- Aging eyes. As we get older our eyes can’t adjust to see close things as well — the reason reading glasses were invented!
- Ordering glasses on the Internet works well and can save a lot of money (hundreds of dollars).
- Removal of cataracts (clouded natural lenses inside the eye) is a 20 minute painless surgery. The old lens is removed and a plastic lens inserted in it’s place. Most people need to wear glasses full or part time after the surgery.
- Diabetes is becoming very common. Diabetes hurts the eyes and may cause blindness. Good control of blood sugar is essential. Laser treatments can slow down some of the deterioration by cauterizing tiny damaged and leaking blood vessels in the retina.
The key numbers are under “Spherical”. These are the strength of the lenses needed measured in diopters. The bigger the number the stronger the lens. A positive number here means you are far-sighted and a negative number means you are near-sighted.
The cylinder is an optical adjustment needed when the natural optics of the eye are not symmetric — the shape of the cornea is not as spherical as it should be — it is a little oblong. The axis is the angle of the oblong abnormality. Any cylinder numbers mean you have this non-spherical problem called astigmatism.
The ADD is the amount of power added to the basic lens strength needed for close-up vision (the lower part of bifocals). +2.5 is typical for seeing things about 14 inches from the eyes (reading) and 1.25 is about right for seeing things about 20 inches from the eyes (computer screens).
The PD (pupilary distance) is important for centering the glasses over the eyes. The right PD is from the bridge of the nose to the center of the right pupil and the left PD is on the opposite side. In most people these are equal and only the sum is important (in this case the sum is 68).
As we get older the eyes can’t adjust well from far to near. People with normal vision may find they just need reading glasses. Near and far sighted people may need bifocals. If you have more than about 0.50 of cylinder adjustment cheap reading glasses will likely not be comfortable and prescription glasses are the solution.
GLASSES on the INTERNET
A couple of reasonable sites are zennioptical.com and 39dollarglasses.com. There are others if you search for them. It’s no big deal to adjust the frames — dipping the bows in near boiling water for 15 seconds then bending them to fit is not difficult — but do not take them to an eye shop for this — they will not help you for obvious reasons. If you have frames that fit make sure to take the measurements suggested on the website and get something similar.
Cataract surgery only takes about 20 minutes and is painless. The clouded lens is removed with a little suction blender then a rolled-up plastic lens is inserted through a needle — it opens up inside the space of the old lens.
Blindness is one of the feared complications of diabetes. It is usually do to an overgrowth of blood vessels in the retina that tend to leak protein and sometimes leak blood — both substances that damage the retina and make holes in the vision. People who keep the blood sugars in tight control tend to have less of this problem. The abnormal blood vessels can be cauterized with a very fine laser which slows down the progression of the condition.