F.Y.EYES ABOUT YOUR EYES
We have included a few F.Y.Eyes (F.Y.I.’s) to help answer many of the questions people have about the eyes, eye health and eye exams. Feel free to contact us with suggestions for other topics you would like to see addressed. We will try to update the website with those suggestions when we can.
Why is it a good idea to wear a mask during COVID-19 and other airborne infection seasons?
Masks are important to stop or slow the spread of infectious diseases that are airborne or spread by talking/coughing/sneezing. COVID-19 is one of those types of infection. But many people refuse to wear their masks thinking they are giving up freedoms by wearing one. The truth from an infectious disease point of view is that anything you can do to reduce contact with an infected person the better off you will be. But we all have jobs and lives to live and can’t avoid interacting with everyone. So the masks help to allow more interaction without allowing the disease to spread so easily.
In all infectious diseases there is a “threshold dose” of the disease agent needed to create illness. If you have a compromised immune system then that dose will be smaller than someone with a robust immune system. But, if you receive some of a virus or bacteria or fungus and it is lower than the threshold dose, you will likely not get sick. Your body will fight off the offending agent and potentially develop immunity to it in the process. So, if an infected person is talking near another person and neither is wearing a mask, then the infectious particles (virus) spread through the air and the healthy individual is likely to catch the infection and get sick. If the sick person is wearing a mask and it reduces virus transmission by about 50% of the virus out of the air and traps it in the mask, then the healthy person is exposed to 50% less of the virus. If the healthy person also wears a mask that reduces virus transmission by about 50% then they will be exposed to about 25% of the virus that they would be exposed to if not wearing any masks. If the masks are better, like N95 masks, then the amount of virus you inhale can be only 0.25% of what you would get if neither is wearing a mask. At some point you will reduce the amount of virus to be below a threshold dose. You will still be exposed to some virus and will likely build immunity to it and won’t become sick. If you become immune, you become one of the “herd” in “herd immunity” and you reduce the transmission of the disease at that point to other people.
COVID-19 (and other viruses and bacteria) can also transmit on surfaces that someone else coughed on or licked, etc. That is why cleaning your hands is of value. If you never touched your face, you probably wouldn’t have to clean so often. But you really should clean your hands before touching your face after being in public to avoid giving yourself a threshold dose of something you don’t want.
But if everyone wore a mask we would be able to get back to a fairly normal life and do it much more quickly because the virus would spread but potentially infect far fewer people and herd immunity would render it ineffective at some point. So wear a mask everyone and let’s get over this faster.
Why is Sleeping in my Contacts a bad idea?
Many people like to sleep in their contacts. Advances in lens materials have made overnight wear much safer than it used to be. However, we still see a much higher incidence of eye infections and other problems (including blood vessel growth where it shouldn’t be) in patients that sleep in their contact lenses. It takes much more overnight wear in the new lenses to cause the problems we used to see in patients with the older materials. But we still see the same problems. Why is that? The new lenses are much more breathable and allow much more oxygen from the environment to penetrate to the surface of the eye. The FDA monitors permeability very closely when they determine if a lens is OK to sleep in. However, sleeping is usually done with the lids closed, so oxygen isn’t getting to your cornea anyway when you are asleep, even without contact lenses on.
Which water would you prefer to have on your eyes?
I don’t believe oxygen permeability is the main factor affecting eye health. I believe, and this is still just a theory, that the real problem is fluid exchange from behind the lens is not able to occur fully. When you put a contact lens on your eye, it has some saline solution in it and your eye also has a layer of tears that get trapped behind the lens. Every time you blink, a little bit of the fluid behind the lens is exchanged with new tears; this is fluid exchange. The fluid exchange occurs around the outside edges of the lens but can’t happen for the main body of liquid trapped under the center of the lens. Because lenses often times adhere like a small suction cup to the cornea, total fluid exchange is unlikely to ever occur. As a result, a portion of the fluid (maybe 10% or maybe 90%) that is trapped behind the lens remains behind the lens as long as you keep your contact lens on your eye. Your tears have proteins and enzymes in them, and often times bacteria and viruses as well. When liquid is trapped on the front of your eye, those impurities become stagnant, like a pond, and likely become toxic over time. It is just like placing a glass of somewhat dirty water in a cup and leaving it alone for a week, or a month, etc. It becomes quite rancid. Rancid or stagnant water on the surface of the eye would be very toxic to the survival of the cornea and thus can cause damage the longer it is kept in contact with your eye. The longer you wear your Extended Wear contact lenses, the longer you allow rancid water to stay in contact with your eye. This is why I never recommend leaving contacts in your eye longer than 6 nights (and often less if I detect any signs of problems from overwear, even if it is only 1-2 nights). Take them out AT LEAST weekly to replace that old water with clean, new water. Daily removal is the best option still for the health of your eyes and the method I recommend to all my patients.
What do Nearsighted and Farsighted mean?
Everyone is either Nearsighted or Farsighted. It refers to what you can see clearly. If you are Nearsighted, you can see things near you the best. If you are Farsighted, you can see things far away from you the best. Nearsighted people can read very easily but cannot see far away without the help of glasses. Their eyes are too powerful and focus light in front of the retina (part of the eye that sees light). Their glasses do not increase focusing power (which happens when an image is made bigger), their glasses will make images appear smaller. Farsighted people can see far away very easily but have to strain the eyes to see up close. They can often see far away and up close at a young age. Eventually, the eyes get tired of being stressed so much and they no longer focus up close as well. At this point, farsighted people will have eye strain and headaches unless they use glasses for near work. Farsighted eyes are too weak and focus light behind the retina. Their glasses will make objects appear larger as they help increase focus and reduce stress on their eyes.
What is Astigmatism?
Having Astigmatism means that the front of your eye is no longer shaped like a perfect basketball. It means the eye is shaped a bit more like the side of a football or rugby ball. The more astigmatism you have, the worse your vision is both far away and up close. Astigmatism also causes eye strain and headaches for people when it isn’t corrected.
Will I need to have my eyes dilated?
Dilating the pupils allows a much easier view into the eye. There are times it is required due to small pupils or damaged structures that make it difficult to see into the eye with standard methods. We prefer to take advanced retinal photos of the eye which allow us to more easily detect and consistently monitor most medical conditions of the eye. Occasionally dilation is required. If you have a medical condition like Diabetes or Rheumatoid Arthritis we will often dilate. If you have vision that cannot be improved with glasses, we will dilate to make sure there is not something interfering with vision from inside the eye. If we do some tests but just cannot get consistent responses, we will dilate the eyes to help relax your eye muscles and allow us to get a more exact answer. We try to accommodate most people’s needs and have found that the advanced photos work well for the majority of our patients.
Are there better contact lenses available than the ones I have been wearing?
Every contact lens is unique and some fit one person better than another lens does. But for another person, the opposite lens may feel better. This is why an exam and contact lens fitting is so essential. We can’t assume a lens will work if all we know is the glasses prescription. We have to try the lenses on your eyes and see how they work in your normal life. We give everyone a week to try new lenses to make sure they are working for them.
Can I qualify for LASIK surgery?
Come in and we will do an evaluation to determine if you are a candidate for LASIK. Most people are able to have the surgery done. But not everyone would benefit from the procedure. If you are trying to reduce your dependence on reading glasses, LASIK isn’t likely to help at all. But, if you would like more freedom from your glasses for activities like driving, or sports, or movies, then LASIK is a great option.
How much does LASIK cost?
Every surgery center is different in their charges. We work hard to filter through the many options to select just the best options to present to our patients. The better surgeons usually are slightly more expensive. And it’s like Dr. Czirr always says, “choosing an eye surgeon is like choosing a brain surgeon. You don’t want to go for the cheapest, just the best.” As a result, LASIK surgery currently should be around $4,000 total.
What is Glaucoma?
Glaucoma is the gradual loss of the nerves in your retina that are responsible for vision. The standard cause is thought to be high eye pressure (which is unrelated to high blood pressure). But many people have glaucoma with normal eye pressures. But it could be said that their individual eye pressure is too high for their eyes to handle. This leads to vision loss over time. The standard diagnosis is initially made during a routine eye exam. This is because people generally do not feel glaucoma, and are not aware of it until it has damaged the majority of nerve fibers. We generally watch the eye pressure, the size of the nerve head and cup (this is the C/D ratio and can be thought of as the size of the donut hole compared to the overall size of the donut). There are several other tests that are done for further detailed testing once an initial diagnosis is made. Ask your eye doctor for more detail at your next eye exam.