Optometry Club

 Contact lenses are medical devices that are worn directly on the cornea of the eye to correct vision or for cosmetic purposes. There are various parameters associated with contact lenses that are important for fitting and prescribing the right lenses for individuals. Here are some common parameters: 1. Power (Refraction): Contact lenses are available in different powers to correct nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia. The power is measured in diopters (D) and can be positive (+) or negative (-) depending on the type of vision correction needed. 2. Base Curve (BC): The base curve determines the curvature of the contact lens. It is typically measured in millimeters (mm) and represents the curvature of the inner surface of the lens. The base curve is chosen to match the curvature of the cornea for proper fit and comfort. 3. Diameter (DIA): The diameter of a contact lens is the measurement across the lens from edge to edge. It is usually me...

 Mosquitoes, like many other insects, have compound eyes. Compound eyes are made up of numerous individual photoreceptor units called ommatidia. Each ommatidium consists of a lens, a cornea, a crystalline cone, and a light-sensitive receptor cell.  Mosquito compound eyes are typically large in proportion to their body size and are positioned on the sides of their head. They have a spherical shape and provide mosquitoes with a wide field of vision, allowing them to detect movement in different directions.  The compound eyes of mosquitoes are designed primarily for detecting changes in light intensity and movement rather than forming detailed images. Each ommatidium captures a small part of the overall image, and the mosquito's brain processes the input from multiple ommatidia to form a composite picture of its surroundings. Mosquitoes are attracted to certain stimuli such as heat, carbon dioxide, and chemicals in human sweat, which help them locate potential hosts for bloo...

**1. Sharp, stabbing pain:** This type of pain is often intense and sudden, resembling a sharp object poking the eye. It can be caused by corneal abrasions or foreign bodies on the surface of the eye. Other possible causes include corneal ulcers, uveitis (inflammation of the uvea), or glaucoma. **2. Aching or throbbing pain:** This type of pain is typically characterized by a persistent, dull ache or throbbing sensation. It can be caused by eyestrain, sinusitis, dry eyes, or increased intraocular pressure. Migraine headaches can also cause aching eye pain, often accompanied by other symptoms like sensitivity to light and sound. **3. Burning or stinging pain:** This type of pain is often described as a burning or stinging sensation in the eyes. It can be caused by conditions such as dry eye syndrome, conjunctivitis (pink eye), or exposure to irritants like smoke, chemicals, or allergens. **4. Soreness or discomfort:** This type of pain is generally characterized by a general feeling of ...