When you take a picture with a camera, the lens in the front of the camera allows light to pass through and focus that light on the film that covers the back side of the camera. A picture is taken when the light hits the film. Our eyes work in a very similar way. The front of the eye (the cornea, pupil and lens) is clear, which allows light to pass through. The cornea and lens of the eye focuses the light on the back wall of the eye, the retina. Like the film, the retina is the "seeing" tissue of the eye, sending messages to the brain through the optic nerve, allowing us to see.
Perfect vision is 20/20. A person is legally blind when their better eye's best corrected visual acuity is less than 20/200. A person can also be legally blind if the side vision in their better eye is narrowed to 20 degrees or less. Although someone may be legally blind, some vision still may be useful and helpful for everyday life. Legally blind people may qualify for certain government benefits.
Low vision is not blindness, but is a level of vision below normal (20/70 or worse) that cannot be corrected with conventional glasses. Low vision can interfere with a person's performance of daily activities, including reading or driving.
Ophthalmologists provide comprehensive eye care, including medical, surgical and optical care. They must complete four years of premedical college, four years of medical school, one year of internship and three years of medical and surgical training in eye care.
Optometrists are different from ophthalmologists. Optometrists are specifically educated in an accredited optometry college for four years, but they do not attend medical school. Optometrists may diagnose eye conditions; however, they are usually not licensed to perform surgical eye treatment procedures.
Although an optometrist is a licensed doctor, their expertise is limited to only examining and diagnosing eye diseases, rather than treating them. They do, however, have the ability to examine, diagnose and treat visual conditions, and are able to prescribe glasses and contact lenses.
Ophthalmologists, on the other hand, are Medical Doctors who specialize in vision care. They are skilled in providing a full range of eye care, from prescribing glasses and contacts to intricate and delicate eye surgery.
The American Academy of Ophthalmology and the American Academy of Pediatrics recommend that the first vision screening be conducted for a newborn prior to being discharged from the hospital. Visual function will be monitored by your child's pediatrician during well-child exams (usually at two, four and six months of age). If there are any signs of an eye condition, your child may be referred to an ophthalmologist. Beginning at three years of age (and yearly after five years of age), amblyopia (poor vision in an otherwise normal appearing eye), refractive and alignment screenings should take place. If you notice any signs of decreased vision or misalignment of the eye, please contact your ophthalmologist for a complete eye examination.
We recommend adult examinations of the eyes be performed on a regular basis. Below is a chart with a recommended time line of how often an adult should receive an eye examination.
Ages 65 and older
Every three to five years.
Every two to four years.
Every one to two years.
Yes, poor vision can be directly related to your family's history of eye health. It is important to see an ophthalmologist at the first sign of poor vision.
No, there is no evidence that television sets produce rays that are harmful to the eyes.
No, there is no evidence that working at a computer can damage the eyes. However, low light, glare on the monitor, or staring at a computer screen too long can cause the eyes to become fatigued. It is recommended to take frequent breaks to allow your eyes to rest.
No, there is no evidence that low light can harm the eye.
Yes, pink-eye (viral conjunctivitis) is very contagious, and very common. To help prevent spreading pink-eye, avoid touching your eyes with your hands, wash your hands frequently, do not share towels, and avoid work, school or daycare activities for a least five days or as long as discharge is present.
No. Presently, there is no medical way to transplant a whole eye.
Wearing UV protective lenses can be beneficial in protecting your eyes from cataract formation. Surprisingly, clear UV coated lenses may offer more protection than darker lenses because they allow the eyes to be exposed to more light causing the pupil to constrict more, which ultimately prevents more light from entering into the eye.
With the advancement in today's technology, there are many new materials available for glasses that have helped make them virtually indestructible. Titanium frames and polycarbonate frames are two of the newest materials used. Polycarbonate materials, glass and various types of lightweight plastics are used to make the lenses. There are several types of coatings available for lenses, including UV protection (which is highly recommended for all types of lenses), polarization, anti-glare and scratch-resistant; just to name a few.
Eye exams may vary from person to person, but here are a few common things we may do during a routine exam:
- Fully review your family history of eye health
- Determine your visual acuity
- Confirm your intraocular pressure
- Examine your pupils' response to light
- Dilate your eyes to properly examine the posterior structures of the eye
Research has shown that eating carrots will provide you with a small amount of vitamin A, which is beneficial for good vision. Other food items that contain Vitamin A include: milk, cheese, egg yolk and broccoli.
It is important to seek immediate medical assistance from either an ophthalmologist or primary care physician if you have an injury. This will help reduce the risk of any permanent damage. To view some general guidelines for properly treating eye injuries, visit our Common Problems page.