Before I entered optometry school I knew there would be some really cool things I would learn and experience throughout my 4 years, knowledge that would be unobtainable elsewhere. Now that I am in school there is not a day that goes by that I don’t learn something that fascinates me. Yet I can only speak for myself and I must admit that I have met a handful people who do not find the coursework of optometry school interesting.
So today I wanted to give you guys a quick checklist of really fascinating things my classmates and I have learned and experienced in our first year of optometry school over the last 6+ months. This is a very brief list and in no way shape or form covers every interesting thing I have learned. The SUNY 2013 class consists of a very intelligent group of individuals who are motivated optometry students and great friends. When I told them I was writing this article, many of them contributed their ideas.
Do you find these things interesting? Do you want to spend your life doing things like this? Does this stuff make you smile or does it put you to sleep?
Although this is a huge generalization, I think it is safe to say that if the list below gets you charged up and excited then Optometry could fit very well into your life. If the list bores you or is lame in any way and you think that you want to live a more exciting lifestyle then perhaps you need to either dig deeper into optometry or choose a different path.
Keep in mind, this list is only from a first year students perspective, there is lots to learn and there is so much that I have left out.
So read this list and then ask yourself; Is optometry for me?
- Despite popular belief visual acuity does not decline with age, but instead remains relatively stable with the mean VA being 20/20. Yet a condition called presbyopia, which occurs in all humans around the ages of 35-55 is due to the crystalline lenses loosing its elasticity and the cilliary muscles loose their power. This means that the patient looses the ability to accommodate and focus on objects close up.
- Air force pilots are chosen to be a least mildly hyperopic because the blue field of the sky activates their tonic accommodation. This would blur an emmetropic patient, yet would make a hyperope perfectly emmetropic!
- There are many different forms of prosthetic eyes. Most commonly a large 16mm contact lens will be inserted into a patients eye and then custom painted to match the patients ocular and facial features. This is common when the patient has severe damage to their eye yet it is still intact. Yet an eye can also be completely removed in 2 different ways. There is evisceration when part of the globe is removed yet the sclera remains and there is exenteration when the globe is removed along with all of the extra ocular muscles, the optic nerve and sometimes part of the boney orbit. Then there is enucleating, which is when just the globe is removed yet the extra ocular muscles are sewn onto a peg like structure, which a prosthetic eye also fits onto. Optometrists oftentimes must ask a patient to remove their prosthetic eye, whether the contact lens form or replacement globe form in order to check ocular health.
- If a patient gets a corneal transplant it can only be a small part of the central cornea that is replaced. If it is any larger then say 8mm then the new transplanted tissue will enter into the vascular limbal region of the cornea and has the potential to be rejected by the body.
- Depending on the situation a patient may be blind and have NLP (no light perception) out of one eye and have good visual acuity in the other eye, the motility of the NLP eye will still work because both eyes work in sync (versions) when being moved by the extra ocular muscles.
- Sunglasses, before they had UV protection where extremely harmful to the eye. The darker conditions increased the dilation of the pupil allowing more harmful UV rays to reach the crystalline lens and fundus.
- The blood vessels within the iris are extremely tough so that when the iris dilates and constricts the blood vessels remain intact and do not burst. This is necessary because these non-fenestrated vessels also maintain the blood eye barrier in the iris.
- It is possible to obtain the visual acuity for an individual who cannot talk, such as an illiterate or a child through various methods such as forced choice preferential looking acuity cards or by attaching electrodes to the scalp and obtaining a VEP (visually evoked potential).
- The visual acuity of a 1 month old is 20/638. It is not until roughly 48+ months that the child has 20/20 vision.
- Keratoconus is a degenerative disorder of the cornea that causes the cornea to take on an extreme cone shape instead of a nice curve. This completely distorts vision often severely reducing visual acuity. Patients have a very poor quality of life, yet keratoconus can be managed with customized rigid gas permeable contact lenses or with a corneal transplant. It is believed that one of the main reasons the cornea takes the shape of a cone is due to the persistent itching and rubbing of the eyes, physically grinding the cornea into a cone shape. This among other factors like genetics and enzymes are believed to be the cause for this mysterious condition.
- If child may only be able to see objects oriented vertically or horizontally if they were born with a severe refractive error with astigmatism. This would cause them to see clear in one meridian and poorly in another meridian. The individual must have been born with this refractive error and it must have gone uncorrected for 2 year of life (the critical period for humans). The striate cortex of the brain will then develop with very poor “orientation columns” for stimuli in the fogged meridian.
- Prosopagnosia is the inability to see faces.
- The eye, specifically the choroid, has the highest blood flow in the entire body. This means that 1,400ml/min/100g of tissue flows through the vessels of the choroid, giving it a higher blood flow then the kidney! One interesting function of this blood flow is that it acts as a heat sink. The photoreceptors generate a very large amount of heat yet it is the blood flow in the choriocapillaris that will take this heat and carry it away from the eye. If this mechanism were not in place, the Q10 protein of the electron transport chain would become over active, causing lysozomes from the retinal-pigmented epithelium to degrade the rods and cones ultimately leading to blindness.
- The eye, specifically the retina has the highest metabolic rate of any tissue in the body. This is because light is constantly stimulating the photoreceptors (rods and cones) causing them to send impulses to the dLGN and striate cortex of the brain.
- The cornea is one of the most sensitive tissues in the body, receiving sensory fibers from the ophthalmic division of the trigeminal nerve and short and long cilliary fibers from the ocular motor nerve.
- It is possible for a patient to be allergic to water. The allergy can be to cold or hot water. If this is the case you must seek an alternate form of therapy instead of cold/warm compresses on the eyes of patients.
- Contact lenses have an optical zone in which only the very center has the patients Rx in the lens. The periphery of the lens does not have the Rx and can therefore distort vision is placed in the line of site. Contact Lens companies do this to save money!
- Increased cerebrospinal fluid production within the body often presents itself in the eye by causing increased intraocular pressure and therefore you as an optometrist can pick up on life threatening systemic problems before any other doctor.
- Optometrists must often check a patient’s blood pressure before prescribing drugs that lower intraocular pressure. This is because these IOP lowering drugs can be beta-blockers, which decrease the heart rate and can cause serious complications for the patient. The average heart rate is roughly 60 beats per minute. Levels drastically above this are labeled Tachycardia and levels drastically below this are labeled bradycardia. Very active athletes often have a lower heart rate. You will learn to check blood pressure in optometry school.
- In premature births, babies are often given supplemental oxygen and this enhanced oxygen, in an undeveloped eye can cause retinal blood vessels to be pulled tight leading to retinal disorders. Premature births can also result in no cilliary body function and therefore no aqueous production within the eye.
- Diabetes can be seen in the retina, specifically the outer plexiform layer (the location of synapses between photoreceptors and horizontal / bipolar cells. The doctor will see “dot and blot” hemorrhages named due to their appearance. This can come from type 1 or type 2 diabetes where excess blood glucose rises and pericytes are destroyed and leakage of blood occurs. The oxygen can then not get to the retina and hypoxia occurs. Therefore new blood vessels grow but these too are leaky and the problem never fixes itself.
- Submarines ships and dark photography rooms often use a light emitting a wavelength of 700nm, a red light, because this light exhibits the lowest luminosity while still providing enough light to see. The reason being is because individuals in submarines and dark rooms go from dark conditions to light conditions and do not have time to adjust. The red wavelength allows the room to be dark enough but it does not fully dark adapt the eye. Due to this red light, changing from dark to light conditions is not as harsh on the visual system and hence prevents accidents from occurring.
- The eye is the only place in the body where you can clearly see blood vessels in situ without cutting into the tissue. Optometrists are therefore the first people to spot high blood pressure, diabetes, potential strokes, brain tumors and other life threatening systemic conditions. I would say that 80% of the optometrists I have talked to have actually saved a patients life because they recognized a life threatening condition and sent them to the hospital immediately.
Do you have any cool stuff to contribute? Comment below!