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Eye-Q

Stop by and learn about your eyes!


Questions will be featured on our Madison Eye Care – Lakewood Facebook page
Answers will be posted here on our website

Q: Which of these structures is a part of the human eye?
1. Trabecular meshwork
2. Schlemm’s canal
3. Aqueous veins of Ascher
4. Ciliary body

ANSWER:
It is a trick question since all are parts of the aqueous drainage system of the eye. The aqueous humor is a watery fluid that fills the front of the eye. The production and drainage of the aqueous establishes and maintains the pressure inside the eye. A disruption of this delicate balance can result in an elevation of the internal pressure of the eye. If the pressure gets high enough then permanent damage occurs to the optic nerve. This is glaucoma.

Q: The “blind spot” of our eye corresponds to:
the retina
the macula
the optic nerve
the pupil

ANSWER:
It actually corresponds to the optic nerve. The retina is made up of many cells called photoreceptors (rods and cones). They convert light energy to an electrical impulse or signal. The information travels to other cells (ganglion cells) in the retina. Eventually all these cells come together to make up the optic nerve. The optic nerve then takes the information to the brain where it is analyzed and perceived as an image. Since the optic nerve has no photoreceptor cells, it is not capable of seeing and thus creates a “blind spot” in our vision.

Q: The most common eye color is:
Blue
Green
Brown
Hazel

ANSWER:
The most common eye color is brown. The iris is the name of the colored part of the eye. It is named after the Greek word for rainbow. The color of our eyes is determined by the amount of pigment (melanin) and the thickness of the collagen fibers in the stroma of the iris. Brown eyes have the most pigment and blue eyes have the least. Babies’ eyes are blue at birth because the melanin pigment is deep in the iris and it gradually moves closer to the surface and then changes eye color.

Eye color is an inherited trait. Brown is considered a dominant gene. This means that if either parent contributes a brown eye gene then the child will have brown eyes. For blue or green eyes, you must inherit a recessive gene from both parents.

Q: Which is the strongest optical element in the eye?
1. Tears
2. Cornea
3. Lens

ANSWER:
The cornea contributes the most to the power or strength of the eye as an optical system. The crystalline lens only contributes about a quarter of the power. Our tears are also part of the eyes optical system. The cornea is the clear front part of the eye. It curves above the iris (the colored part of the eye) like a watch crystal. The surface of the cornea is irregular and would not be a good optical surface by itself. Our tears fill in all the irregularities in the cornea and make it into a smooth surface with good optics.